# ICHEP2012

Australia/Melbourne
Melbourne Convention and Exhibition Centre

#### Melbourne Convention and Exhibition Centre

Melbourne Australia
,
Description
36th International Conference on High Energy Physics.
Support
• Wednesday, 4 July
• 15:00 18:00
ATLAS talk prep Conference Room Level 7 (David Caro, University of Melbourne)

### Conference Room Level 7

#### David Caro, University of Melbourne

closed meeting

• 15:00 19:30
Registration
• 18:00 19:30
Welcome Reception
• 22:00 23:30
CMS Meeting Conference Room, Level 7 (David Caro, University of Melbourne)

### Conference Room, Level 7

#### David Caro, University of Melbourne

closed meeting

• Thursday, 5 July
• 09:00 18:00
TR 12 - Formal Theory Development & TR 1 - The Standard Model Room 218

### Room 218

#### Melbourne Convention and Exhibition Centre

Melbourne Australia
• 09:00
Scattering in Planar N=4 Super-Yang-Mills Theory and the Multi-Regge Limit 20m
Scattering amplitudes in N=4 Super-Yang-Mills theory are tightly constrained by several general principles: Dual (super)conformal invariance, an operator product expansion for the leading singularity, discrete symmetries, the properties of transcendental functions, and various kinematic limits. Remarkably, these onstraints can be combined to almost completely determine the six-gluon scattering amplitude at three loops, as well as provide important information beyond three loops, without ever directly evaluating any loop integrands or loop integrals. The general constraints work in synergy with those arising in a specific limit --- multi-Regge-kinematics for high-energy scattering --- and shed new light on this limit.
Speaker: Prof. Lance Dixon (SLAC National Accelerator Laboratory (US))
• 09:20
Maximal Unitarity at Two Loops 20m
The unitarity method is a key part of the set of on-shell methods for calculating gauge-theory amplitudes both analytically and numerically. These methods have been used successfully to obtain the one-loop amplitudes needed for a variety of cutting-edge high-multiplicity next-to-leading order calculations for LHC physics. They have been applied both to analytic calculations, and in the framework of numerical codes such as BlackHat. In this talk, I discuss the first steps in extending maximal unitarity to a computation of two loop amplitudes, needed for precision LHC calculations.
Speaker: Dr David Kosower (CEA - Centre d'Etudes de Saclay (FR))
• 09:40
Spectrum of a Walking Gauge Theory 20m
We study the spectrum of vector and scalar mesons in the holographic dual of a walking gauge theory , obtained by embedding D7 - anti-D7 probe branes in a certain type IIB background. We show that there is a nontrivial relation that needs to be satisfied in order for axial-vector modes to exist The scalar mesons arise from fluctuations of the probe flavour branes and complement the (axial-)vector meson spectra. By explicitly finding the spectrum of scalar masses, we show that the nonsupersymmetric D7 - anti-D7 embedding is stable with respect to such fluctuations. Interestingly, it turns out that the mass splitting between the scalar and vector meson spectra is of subleading order in a small parameter expansion. We also estimate the Peskin Takeuchi S parameter of this theory and show that it is positive definite.
Speaker: Prof. L.C. Rohana Wijewardhana (University of Cincinnati (US))
• 10:00
Holographic calculation of hadronic contributions to muon g-2 15m
We have performed a holographic calculation of the hadronic contributions to the anomalous magnetic moment of the muon, using the gauge/gravity duality. We compute the leading order hadronic (HLO) contribution to the anomalous magnetic moment of muon, amu(HLO), and find amu(HLO) =470.5 x 10^{-10} in AdS/QCD with two light flavors, which is compared with the currently revised BABAR data estimated from e^+ e^- -> pi^+ pi^- events, amu(HLO)[pipi]=(514.1 +- 3.8) x 10^{-10}. Calculating the light-by-light contribution, both 5D SU(2) and U(3) flavor gauge symmetries are considered for the neutral pion, eta and eta' contributions to the hadronic corrections. We find the total light-by-light contributions of pseudo scalars to the muon anomalous magnetic moment, a_mu=10.7 x 10^(-10), which is consistent with previous estimates, based on other approaches.
Speaker: Dr Doyoun Kim (Monash University (AU))
• 10:15
Strong field effects on physics processes at the Interaction Point of future linear colliders 15m
Future linear colliders will be precision machines which, among other things, will closely study the Higgs sector, provide tighter bounds on electroweak observables and look for new physics via polarised beams. The luminosity requirements of such machines entail very intense lepton bunches at the IP with associated strong electromagnetic fields. These strong fields not only lead to obvious phenomena such as beamstrahlung, ISR and FSR, but also affect every particle physics process via virtual exchange with the bunch fields. For precision studies, strong field effects have to be understood to the sub-percent level. Strong external field effects can be taken into account exactly via the Furry interaction Picture. Within this picture, significant theoretical and phenomenlogical development is in progress and here we summarise the current state of play, presenting new exact solutions for overlapping relativistic charge bunch fields, cross-sections calculations for generic two vertex Furry picture processes, and the generation of processes via a new software package - IPstrong.
Speaker: Dr Anthony Hartin (DESY (DE))
• 10:30
Refreshment Break 30m
• 11:00
IR-Improved Operator Product Expansions in non-Abelian Gauge Theory 15m
We present a formulation of the operator product expansion that is infrared finite to all orders in the attendant massless non-Abelian gauge theory coupling constant, which we will often-times associate with the QCD theory, the theory that we actually have as our primary objective in view of the operation of the LHC at CERN. We make contact in this way with the recently introduced IR-improved DGLAP-CS theory and point-out phenomenological implications accordingly, with an eye toward the precision QCD theory for LHC physics.
Speaker: Prof. Bennie Ward (Baylor University (US))
• 11:15
Radiation from accelerated charges at strong coupling 15m
We present our latest results concerning the radiation spectrum emitted by a relativistic charged particle at strong coupling, employing the theoretical techniques provided by the AdS/CFT correspondence. We compare with other recent analyses of this problem with heavy quarks [1,2], and in our case we do find deviations from the (classical) Lienard formula once we take into account all the relevant quantum effects. References: [1] C.Athanasiou, P.M.Chesler, H.Liu, D.Nickel and K.Rajagopal, Synchrotron radiation in strongly coupled conformal field theories,'' Phys. Rev. D81, 126001 (2010). [2] Y.Hatta, E.Iancu, A.H.Mueller and D.N.Triantafyllopoulos, Aspects of the UV/IR correspondence: energy broadening and string fluctuations,'' JHEP 1102, 065 (2011).
Speaker: Dr Daniel Fernandez-Fraile (Frankfurt University (DE))
• 11:30
Near BPS Skyrmions: Non-shell configurations and Coulomb effects 15m
We propose to describe nuclei as near BPS solitons emerging from a generalization of the Skyrme model in the regime where a sixth-order term and a generalized mass term dominate. The mass term is chosen such that the baryon and energy density generated by the solutions do not exhibit the usual shell configuration. Adding contributions from the rotational energy, Coulomb energy and isospin symmetry breaking, we reproduce the mass of the most abundant isotopes to rather good accuracy.
Speaker: Prof. Luc Marleau (Université Laval (CA))
• 11:45
Classical geometry to quantum behavior correspondence in a Virtual Extra Dimension 15m
In the Lorentz invariant formalism of compact space-time dimensions the assumption of periodic boundary conditions represents a consistent semi-classical quantization condition for relativistic fields. In [arXiv:1110.0315, Ann. Phys. (2012)] we have shown, for instance, that the ordinary Feynman path integral is obtained as interference between the classical paths with different winding numbers associated to the cyclic dynamics of the field solutions. Through the boundary conditions, the kinematical information of interaction is encoded on the relativistic geometrodynamics of the boundary. Furthermore, such a purely four-dimensional theory is manifestly dual to an extra-dimensional field theory. The resulting correspondence between extra-dimensional geometrodynamics and ordinary quantum behavior yields an unconventional interpretation of the AdS/CFT correspondence in terms of wave-particle duality. By applying this approach to a simple Quark-Gluon-Plasma freeze-out model we retrieve basic aspects of AdS/QCD phenomenology.
Speaker: Dr Donatello Dolce (University of Melbourne (AU))
• 12:00
Calculating repetitively 15m
The Antonsen – Bormann idea was originally proposed by these authors for the computation of the heat kernel in curved space; it was also used by the author recently with the same objective but for the Lagrangian density for a real massive scalar field in 2 + 1 dimensional stationary curved space,the metric being defined by the rotating solution of Deser et al. Ann.Phys.120,220(1984) and Clement,Int.J.Theor.Phys.24,267(1985) of the Einstein field equations associated with a single massless spinning particle located at the origin.It is now reworked here with a different purpose – namely, to determine the zeta function for the said model using the Schwinger operator expansion. The repetitive nature of this calculation at all higher orders (≥3) in the gravitational constant G suggests the use of the Dirac delta-function and one of its integral representations – in that it is convenient to obtain answers. The vierbeins presented by the author at FFP10 – arXiv: 1003.0260 [hep-th] – and published in Kamath, AIP Conf.Proc.1246: 174-177, 2010 play a pivotal role in this exercise, with the pair displayed in eq.(12) therein being distinguished for the simplicity of the calculation reported here.
Speaker: Prof. Gopinath Kamath (Indian Institute of Technology-Madras (IN))
• 12:15
NLO and NNLO EWC for PV Møller Scattering 15m
High-precision electroweak experiments such as parity-violating Møller scattering can provide indirect access to physics at multi-TeV scales and play an important complementary role to the LHC research program. However, before physics of interest can be extracted from experimental data, electroweak radiative corrections, which can significantly reduce the cross-section asymmetry, must be calculated with an unprecedented completeness and accuracy. Although the two-loop corrections are strongly suppressed relative to the one-loop corrections, they can no longer be dismissed. We evaluate a full gauge-invariant set of one-loop and several types of the two-loop radiative corrections for the Møller asymmetry by combining two distinct but mutually-reinforcing techniques: semiautomatic, precise, with FeynArts and FormCalc as base languages, and “by hand”, with some approximations. For 11 GeV relevant for the MOLLER experiment planned at JLab, the results obtained by two approaches are in excellent agreement, which gives us assurance that our calculations are error-free. A possible way to incorporate new physics particles into theoretical predictions for the Møller asymmetry is briefly discussed at the end.
Speaker: Dr Svetlana Barkanova (Acadia University (CA))
• 12:30
Lunch Break 1h 30m
• 14:00
Supersymmetry breaking from monopole condensation 20m
I will describe models where dynamical supersymmetry breaking is triggered by monopole condensation. Low energy theory is described by O'Rafeartaigh models with spontaneously broken R-symmetry.
Speaker: Prof. Yuri Shirman (University of California-Irvine (US))
• 14:20
Higher Spins and Strings 20m
The formulation of consistent theories involving particles with arbitrary spin represents an old open theoretical challenge. In the massless case the corresponding gauge theories provide far-reaching generalisations of Yang-Mills theory and General Relativity, while massive higher-spin states are known to represent essential ingredients of the spectrum of String Theory. I will describe the basics of higher-spin constructions in flat and (Anti-) de Sitter backgrounds and review some recent progress on the subject, aiming to better frame the question of how to provide a bridge between the massless regime and its possible broken phases.
Speaker: Dr Dario Francia (Centro E. Fermi and Scuola Normale Superiore (IT))
• 14:40
An Estimate of Lambda in Resummed Quantum Gravity in the Context of Asymptotic Safety and Planck Scale Cosmology: Constraints on SUSY GUTS 15m
We use the amplitude-based resummation of Feynmans formulation of Einsteins theory to arrive at a UV finite approach to quantum gravity. We show that we recover the UV fixed point recently claimed by the exact field-space renormalization group approach. We use our approach in the context of the attendant Planck scale cosmology formulation of Bonanno and Reuter to estimate the value of the cosmological constant as \rho_\Lambda=(0.0024 ev)^4. We show that the closeness of this estimate to experiment constrains susy GUT models.
Speaker: Prof. Bennie Ward (Baylor University (US))
• 14:55
Finite Energy One-half Monopole Solutions of the SU(2) Yang-Mills-Higgs Theory. 15m
We would like to show the existence of finite energy SU(2) Yang-Mills-Higgs particles of one-half topological charge. The 't Hooft Abelian magnetic fields of these solutions at spatial infinity correspond to the magnetic field of a positive one-half magnetic monopole located at the origin, $r=0$, and a semi-infinite Dirac string singularity located on one half of the $z$-axis which carries a magnetic flux of $\frac{2\pi}{g}$ going into the center of the sphere at infinity. Hence the net magnetic charge of the configuration is zero. The non-Abelian solutions possess gauge potentials that are singular at only one point, that is, on either the positive or the negative $z$-axis at large distances, elsewhere they are regular. There are two distinct different configurations of these particles with different total energies and energy distributions. The total energies of these one-half magnetic monopole solutions are calculated for various strength of the Higgs field self-coupling constant $\lambda$ and they are found to increase logarithmically with $\lambda$. These solutions do not satisfy the first order Bogomol'nyi equations and are non-BPS solutions.
Speaker: Prof. Rosy Teh (Universiti Sains Malaysia (MY))
• 15:10
Electric, Magnetic and Spin-Dependent Dynamical Polarizabilities of Hadrons 15m
Compton scattering offers a unique opportunity to study the dynamical structure of hadrons over a wide kinematic range, with polarizabilities characterizing the hadron’s active internal degrees of freedom. We present calculations and detailed analysis of electric and magnetic and the spin-dependent dynamical polarizabilities for the lowest in mass SU(3) octet of baryons. These extensive calculations are made possible by the recent implementation of semi-automatized calculations in chiral perturbation theory which allows evaluating polarizabilities from Compton scattering up to next-to-the-leading order. The dependences for the range of photon energies covering the majority of the meson photoproduction channels are analyzed.
Speaker: Dr Aleksandrs Aleksejevs (Memorial University of Newfoundland (CA))
• 15:25
Refreshment Break 35m
• 16:00
NNLL resummation for W-boson production at large pT 15m
I present new results for W-boson production at large transverse momentum at the LHC and the Tevatron. The contribution of soft-gluon corrections is derived from NNLL resummation and added to the exact NLO result. Numerical results for the approximate NNLO W-boson transverse momentum distributions are derived. The scale and PDF uncertainties are discussed.
Speaker: Prof. Nikolaos Kidonakis (Kennesaw State University (US))
• 16:15
Precise measurement of the W boson mass at CDF II 15m
The mass of the W boson is sensitive to radiative corrections from the top quark and the Higgs boson. We present a new measurement of mW using 2.2/fb of sqrt(s)=1.96 TeV ppbar collision data collected with the CDF II detector. Utilizing 470126 W → eν candidates and 624708 W → μν candidates, we measure mW = 80387±19 MeV. This is the most precise measurement of mW, more precise than all previous measurements of mW combined.
Speaker: Prof. Ashutosh Kotwal (Duke University (US))
• 16:30
Measurement of the W boson mass with the D0 detector and combination of the CDF and D0 results for the W boson mass 15m
We present a measurement of the W boson mass using data corresponding to an integrated luminosity of 4.3 fb-1 collected with the D0 detector during Run 2 at the Fermilab Tevatron ppbar collider. With a sample of 1,677,394 W---> e nu candidate events, we measure M_W = 80.367 +/- 0.026 GeV. This result is combined with an earlier D0 result determined using an independent Run 2 data sample, corresponding to 1 fb-1 of integrated luminosity, to yield M_W=80.375+/-0.023 GeV.We also present the combination of all the Tevatron measurements of the W boson mass, including the results from CDF and from Run I, to obtain the Tevatron average for the mass of the W boson of 80.387 +/- 0.016 GeV and the new world average, including the data from LEP II, M_W=80.385 +/- 0.015 GeV.
Speaker: Dr Jan Stark (Laboratoire de Physique Subatomique et de Cosmologie)
• 16:45
Measurement of tau polarization in W-->tau nu decays with the ATLAS detector 15m
A measurement of tau polarization in W-> tau nu decays is reported with data collected by the ATLAS experiment. It is measured from the energies of the decay products in hadronic tau decays with a single final state charged particle, and it is found in agreement with the Standard Model prediction.
Speaker: Dr Sarah Marie Demers (Yale University (US))
• 17:00
Study of tau-pair production at HERA 15m
A study of events containing two tau leptons with high transverse momentum has been performed with the ZEUS detector at HERA, using a data sample corresponding to an integrated luminosity of 0.33 fb-1. The tau candidates were identified from their decays into electrons, muons or hadronic jets. The number of tau-pair candidates has been compared with the prediction from the Standard Model, where the largest contribution is expected from Bethe-Heitler processes. The total visible cross section was extracted. Standard Model expectations agree well with the measured distributions, also at high invariant mass of the tau pair.
Speaker: Mr Masaki Ishitsuka (Tokyo Institute of Technology)
• 17:15
Elastic Z0 production at HERA 15m
A search for events ep-> ep Z0 has been performed in ep collisions at HERA using the ZEUS detector. The search is based on the entire HERA-I and HERA-II data set, amounting to 0.49 fb-1 of integrated luminosity. The Z0 was searched in the di-jet decay mode with elastic condition defined by etamax < 3, where etamax is defined as the pseudorapidity of the energy deposit in the calorimeter closest to the proton beam direction. A di-jet mass peak is observed at the Z0 mass and the number of signal events is extracted from a fit to the mass spectrum.The elastic Z0 production cross section is determined and compared to the SM prediction.
Speaker: Dr Katarzyna Wichmann (DESY)
• 17:30
Onset of deconfinement and search for the critical point of strongly interacting matter at CERN SPS energies 15m
The exploration of the QCD phase diagram particularly the search for a phase transition from hadronic to partonic degrees of freedom and possibly a critical endpoint, is one of the most challenging tasks in present heavy-ion physics. As observed by the NA49 experiment, several hadronic observables in central Pb+Pb collisions at the CERN SPS show qualitative changes in their energy dependence. These features are not observed in elementary interactions and indicate the onset of a phase transition in the SPS energy range [1,2]. The existence of a critical point is expected to result in the increase of event-by-event fluctuations of various hadronic observables [3,4] provided that the freeze-out of the measured hadrons occurs close to its location in the phase diagram and the evolution of the final hadron phase does not erase the fluctuations signals. A selection of NA49 results on particle multiplicity, transverse momentum, azimuthal angle fluctuations and the proton intermittency from the scan of the phase diagram will be presented and discussed [5,6]. A new technique to study fluctuations of the chemical composition of the hadronic system produced in nuclear collisions, the identity method, will be introduced and its properties will be discussed. Preliminary results from Pb+Pb collisions registered by the NA49 experiment at the CERN SPS will be shown. References: [1] C. Alt et al., Phys. Rev. C 77 (2008) 024903 [2] M. Gazdzicki et al., J. Phys. G 30 (2004) S701 [3] M.A.Stephanov,K.Rajagopal,E.V.Shuryak, Phys.Rev. D 60, 114028 (1999). [4] B.Berdnikov,K.Rajagopal, Phys. Rev. D 61, 105017 (2000). [5] T.Anticic et al., Phys. Rev. C 79, 044904 (2009). [6] C.Alt et al., Phys. Rev. C 78, 034914 (2008).
Speaker: Maciej Rybczynski (Jan Kochanowski University (PL))
• 17:45
. 15m
• 09:00 18:00
TR 6 - RM 217 - QCD, Jets, Parton Distributions Room 219

### Room 219

#### Melbourne Convention and Exhibition Centre

Melbourne Australia
• 09:00
Measurement and QCD Analysis Deep-Inelastic Scattering at HERA. 15m
The inclusive e±p single and double differential cross sections for neutral and charged current processes are measured with the H1 detector at HERA. The data were taken at a centre-of-mass energy of √s = 319 GeV with a total integrated luminosity of 329.1 pb−1 shared between two lepton beam charges and two longitudinal lepton polarisation modes. The differential cross sections are measured in the range of four-momentum transfer squared, Q2 , between 120 and 50 000 GeV2 , and Bjorken x between 0.008 and 0.65. The measurements are combined with earlier published H1 data to determine the structure function xF_3^γ Z. A measurement of the neutral current parity violating structure function F_2^γ Z is presented for the first time. The polarisation dependence of the CC total cross section for Q2 > 400 GeV2 is found to be consistent with the Standard Model. The new measurements are well described by a next-to-leading order QCD fit using all published H1 inclusive cross section data which is used to extract flavour separated parton densities. A measurement is presented of the inclusive neutral current e±p scattering cross section using data collected by the H1 experiment at HERA during the years 2003 to 2007 with proton beam energies Ep of 920, 575, and 460 GeV. The kinematic range of the measurement covers low absolute four-momentum transfers squared, 1.5 GeV2 < Q2 < 120 GeV2, small values of Bjorken x, 2.9 • 10−5 < x < 0.01, and extends to high inelasticity up to y = 0.85. The structure function FL is measured by combining the new results with previously published H1 data at Ep = 920 GeV and Ep = 820 GeV. The new measurements are used to test several phenomenological and QCD models applicable in this low Q2 and low x kinematic domain. A precise knowledge of the integrated luminosity of the HERA collider is relevant for various types of cross section measurements and for a precise determination of the parton density functions of the proton. At ep colliders, the integrated luminosity is often measured in the Bethe Heitler process, using dedicated detectors located at small angles. In this paper, an alternative measurement of the integrated luminosity is presented, exploiting the elastic QED Compton process ep -> e gamma p. Both the electron and the photon are detected in the H1 backward calorimeter. The integrated luminosity of the data recorded in 2003 to 2007 is determined with a relative precision of +-0.85%(stat) +-2.12%(sys), where (stat) is the statistical uncertainty and (sys) is the total systematic uncertainty. The measurement is found to be compatible with the corresponding Bethe-Heitler analysis.
Speaker: Mr Zhiqing Philippe Zhang (Laboratoire de l'Accélérateur Linéaire (FR))
• 09:15
High Q2 Neutral Current new results from ZEUS 15m
The cross sections for neutral current deep inelastic scattering in e+p collisions with a longitudinally polarised positron beam have been measured using the ZEUS detector at HERA. The single-differential cross-sections dsigma/dQ2, dsigma/dx and dsigma/dy and the double-differential cross sections in Q2 and x are measured in the kinematic region Q2 > 185 GeV2 for both positively and negatively polarised electron beams and for each polarisation state separately. The measurements are based on an integrated luminosity of 136 pb-1 taken in 2006 and 2007 at a centre-of-mass energy of 318 GeV. The structure functions xF_3 and xF_3^{\gammaZ} are determined by combining the e+p results presented in this analysis with previously measured e-p neutral current data. The measured cross sections are compared to the predictions.
• 09:30
HERAPDF 15m
A preliminary global NLO QCD analysis of the HERA data is presented. The following data sets are used in this analysis: the NC and CC inclusive DIS cross sections obtained from the combination of the measurements from H1 and ZEUS based on HERA I and HERA II data at the nominal proton beam energy, the preliminary combined inclusive NC DIS cross sections at reduced proton beam energies, the inclusive jet cross sections from H1 and ZEUS and the preliminary combined HERA results on the structure function F2(charm). A NLO QCD PDF fit analysis with simultaneous determination of the strong coupling constant $\alpha_s(M_Z)$ is presented. The analysis is based on the same combined H1 and ZEUS inclusive DIS measurements as HERAPDF1.5 fit, together with jet measurements provided by both H1 and ZEUS collaborations. The inclusion of jet data in the analysis significantly reduces the correlation etween the gluon parton density function and the strong coupling, improving the precision of the gluon PDF and providing an accurate determination of $\alpha_s(m_Z)$. The PDF set HERAPDF1.5 represents the QCD analysis of the combined HERA I including the preliminary combination of the HERA II data. Such, higher precision at high Q2 and high x is achieved. The precision of the PDFs at high x is significantly improved, particularly in the valence sector. The results of the NNLO fit variant are presented: the PDFs and their uncertainties. The fit was performed with 14 free PDF parameters. There are also comparisons to the previous HERAPDF1.0 NNLO PDF, based on HERA I data only, and to the new HERAPDF1.5f, which is a NLO version with also 14 free parameters in the fit. A next-to-leading order QCD analysis is performed based on the preliminary combination of the H1 and ZEUS F2c measurements together with the published HERA inclusive neutral and charged current cross sections. Different variable flavour number schemes were used for the heavy flavour treatment. The fits are used to estimate the optimal value of the charm quark mass parameter mc^model within a given heavy flavour scheme. Depending on the scheme, the optimal values of mc^model range between 1.26 GeV and 1.68 GeV, and are determined with a precision of 0.04 GeV including statistical, model and parameterisation uncertainties.The parton distribution functions determined using the above heavy quark schemes at their optimal values of mc^model are further used to predict the W± and Z production cross sections at the LHC. Good agreement between these predictions for the W± and Z cross sections is observed which allows to reduce the uncertainty due to the heavy flavour treatment, to below 1.0%.
Speaker: Dr Ringaile Placakyte (DESY (DE))
• 09:45
Momentum space dipole amplitude for DIS and inclusive hadron production 15m
We show how the AGBS model, originally developed for deep inelastic scattering applied to HERA data on the proton structure function, can also describe the RHIC data on single inclusive hadron yield for $d+Au$ and $p+p$ collisions through a new simultaneous fit. The single inclusive hadron production is modeled through the color glass condensate, which uses the quark(and gluon)--condensate amplitudes in momentum space. The AGBS model is also a momentum space model based on the asymptotic solutions of the BK equation, although a different definition of the Fourier transform is used. This description entirely in transverse momentum of both processes arises for the first time. The small difference between the simultaneous fit and the one for HERA data alone suggests that the AGBS model describes very well both kind of processes and thus emerges as a good tool to investigate the inclusive hadron production data. We use this model for predictions at LHC energies, which agree quite well with available experimental data.
Speaker: Prof. M. Beatriz Gay Ducati (Universidade Federal do Rio Grande do Sul (BR))
• 10:00
New results on the 3-loop Heavy Flavor Wilson Coefficients in Deep-Inelastic Scattering 15m
We report on recent results obtained for the 3-loop heavy flavor Wilson coefficients in deep-inelastic scattering at general values of the Mellin variable N at large scales of Q^2. These concern contributions to the gluonic ladder-topologies, the transition matrix elements in the variable flavor scheme, and first results on higher topologies. The knowledge of the heavy flavor Wilson coefficients in 3-loop order is of importance to carry out complete NNLO QCD analyses of the world precision data on the structure function F_2(x,Q^2).
Speaker: Dr Abilio De Freitas (DESY Zeuthen (DE))
• 10:15
Partons, QCD and Low x Physics at the Large Hadron electron Collider (LHeC Study Group) 15m
The Large Hadron electron Collider (LHeC) is a proposed facility which will exploit the new world of energy and intensity offered by the LHC through collisions with a new 60 GeV electron beam. This contribution summarises the detailed simulation studies on QCD-related topics included in the recently released Conceptual Design Report. Highlights include a new level of precision and flavour decomposition for the extraction of parton densities and a much extended kinematic range towards low Bjorken-x in which novel saturation effects are expected. In addition to inclusive neutral and charged current cross sections, more exclusive processes such as jet and heavy flavour production are included, as well as diffractive observables.
Speaker: Prof. Claudia Beatriz Glasman Kuguel (Universidad Autonoma de Madrid (ES))
• 10:30
Refreshment Break 30m
• 11:00
Measurements of differential cross sections for W+jets and for multijet production and determination of the strong coupling constant in ppbar collisions at sqrt(s)=1.96 TeV 15m
We present two sets of measurements based on data collected with the D0 detector at the Fermilab Tevatron collider running at sqrt(s)=1.96 TeV. First we present a comprehensive study of the differential cross sections for the production of W bosons in association with up to four hadronic jets. Results are compared with the latest NLO and resummation theoretical predictions as well as with models implemented in event generators. We then present measurements of differential cross sections sensitive to multijet production, which are then interpreted in the framework of QCD to determine the evolution of the strong coupling constant in the energy range between 200 and 450 GeV, which has not been investigate yet in these type of studies.
Speaker: Prof. Michael Strauss (University of Oklahoma (US))
• 11:15
Z+Jets results from CDF 15m
Inclusive Z boson plus jets cross sections, as well as bottom jet production in association with a Z-boson cross sections, are measured in a final state where the Z boson has decayed in two muons or electrons. Results are based on the full data sample collected with the CDF detector in Run II, corresponding to $\sim 9.4$ fb$^{-1}$ of $\rm p\bar{p}$ collisions at $\rm \sqrt{s}$ = 1.96 TeV. Differential cross sections are measured as a function of several variables, among which jet transverse momentum, jet rapidity and jets multiplicity. Measurements are compared to results from different next-to-leading order perturbative QCD predictions and event generators.
Speaker: Dr Konstantinos Vellidis (Fermi National Accelerator Laboratory (US))
• 11:30
Measurements with electroweak gauge bosons at LHCb 15m
We report the results of several analyses based on the reconstruction of electroweak gauge bosons at LHCb. The forward coverage of the LHCb detector provides unique sensitivity to various different observables that can be used to test the Standard Model predictions. The results include those on W and Z production, Z production with associated jets, and low-mass Drell-Yan production.
Speaker: Dr Jonathan Anderson (Universität Zürich (CH))
• 11:45
ATLAS measurements of jets and heavy flavour produced in association with W and Z bosons 15m
The production of jets and/or heavy flavours in association with a W or Z boson represents an important process with which to study QCD in a multi-scale environment. Unprecedented precision is achieved in measurements of differential cross sections and multiplicities, and comparisons are made to state-of-the-art high NLO QCD calculations of high-multiplicity final states. Jets containing b- or c-hadrons are also identified, and correlations are studied.
Speaker: Prof. Pierre-Hugues Beauchemin (Tufts University (US))
• 12:00
Jet production in association with vector bosons 15m
The associated production of jets and vector bosons allows for stringent tests of perturbative QCD calculations and is sensitive to the possible presence of new physics beyond the Standard Model. A measurement of jet production rates in association with W and Z bosons, or photons, in proton-proton collisions at a 7 TeV center-of-mass energy is presented, using data collected with the CMS detector. The measured jet multiplicity distributions corrected for efficiency and unfolded for detector effects are compared with theoretical predictions. Results for the W charge asymmetry as a function of the number of jets and a test of Berends–Giele scaling are also presented.
Speaker: Dr Piergiulio Lenzi (CERN)
• 12:15
QCD studies with W and Z cross sections measured in ATLAS 15m
Precise measurements of W and Z production, differential in pT and rapidity, are shown. These provide stringent tests of higher order QCD, resummed calculations and non-perturbative models. They are also used to extract information on the strange quark content of the proton.
Speaker: Dr Maarten Boonekamp (CEA - Centre d'Etudes de Saclay (FR))
• 12:30
Lunch Break 1h 30m
• 14:00
Jet Physics at HERA 15m
Isolated-photon+jet production in ep collisions at a centre-of-mass energy of 318 GeV has been measured with the ZEUS detector at HERA using an integrated luminosity of up to 300 pb-1. Measurements of prompt-photon+jet cross sections are presented as functions of the photon transverse energy and pseudorapidity in a wide range of exchanged-photon virtuality. In addition, differential gamma+jet cross sections are presented as functions of the jet transverse energy and pseudorapidity. Leading-logarithm parton-shower Monte Carlo predictions and perturbative QCD calculations were compared to the data. Differential inclusive-jet cross sections have been measured in photoproduction for boson virtualities Q2 < 1 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 300 pb-1. Jets were identified in the laboratory using the kt cluster algorithm in the longitudinally inclusive mode. Cross sections are presented as functions of the jet pseudorapidity, etajet, and the jet transverse energy, Etjet. In addition, measurements of double-differential inclusive-jet cross sections are presented as functions of Etjet in different regions of etajet. These cross sections have the potential to constrain the gluon density in the proton and the photon when included as input to fits to extract the proton parton distribution functions. Next-to-leading-order QCD calculations give a good description of the measurements. A value of alphas(Mz) has been extracted from the measurements. The energy-scale dependence of the coupling has also been determined. Signals of QCD instanton-induced processes are searched for in deep-inelastic scattering (DIS) at the electron-proton collider HERA in the kinematic region defined by the Bjorken-scaling variable x > 10^{-3}, the inelasticity 0.2< y < 0.7 and the photon virtuality 150 < Q^2 < 15000 GeV^2. The search is performed using H1 data corresponding to an integrated luminosity of ~350 pb^{-1}. Several observables of the hadronic final state of the events are exploited to identify a potentially instanton-enriched domain. Two Monte Carlo models, RAPGAP and ARIADNE, are used to estimate the background from the standard DIS processes, and the instanton-induced scattering processes are modeled by the program QCDINS. In order to extract the expected signal a multivariate data analysis technique is used. New results on normalised inclusive jet, di-jet and trijet differential cross sections in neutral current deep-inelastic ep scattering (DIS) based on a regularised unfolding procedure are presented. Detector effects like acceptance and migrations as well as statistical correlations between the multi-jets and the inclusive DIS events are taken into account in this procedure. The DIS phase space of this measurement with the H1 detector is given by the virtuality of the exchanged boson (gamma*,Z^0) 150 < Q^2 < 15000 GeV^2 and the inelasticity of the interaction 0.2 < y < 0.7. The jets are reconstructed in the Breit frame of reference using the k_t jet algorithm. In all cases the jet pseudorapidities in the laboratory frame are required to be in the range -1.0 < eta_lab < 2.5. For inclusive jets the transverse momenta in the Breit frame are 7 < P_T < 50 GeV. The di-jet and tri-jet phase space are defined by requiring 5 < P_T,i < 50 GeV, and the invariant mass of the two leading jets M_1,2 > 16 GeV. Compared to a previously published result on normalised multi-jet cross sections, the new features are an extended range in jet pseudorapidity, an improved hadronic energy scale uncertainty of 1% and the adoption of a regularised unfolding procedure. The unfolded normalised jet cross sections are compared to QCD calculations at NLO and values for the strong coupling alpha_s(M_Z) are extracted.
• 14:15
Transverse Energy Energy Correlations in Next-to-Leading Order in alpha_s at the LHC 15m
We compute the transverse energy-energy correlation (EEC) and its asymmetry (AEEC) in next-to-leading order (NLO) in $\alpha_s$ in proton-proton collisions at the LHC with the center-of-mass energy $E_{\rm c.m.}=7$ TeV. We show that the transverse EEC and the AEEC distributions are insensitive to the factorization- and renormalization scales, the underlying minimum bias events, and the structure functions. Hence they can be used to precisely test QCD in hadron colliders and determine $\alpha_s$. We illustrate this technique by defining jets using the anti-$k_T$ jet algorithm and an event selection procedure typically used in the analysis of jets at the LHC and show the $\alpha_s$-dependence of the transverse EEC and the AEEC in the range $0.11 \leq \alpha_s(M_Z) \leq 0.13$.
Speaker: Prof. Ahmed Ali (DESY (DE))
• 14:30
ATLAS jet measurements, and subjet structure for boosted hadronic objects 15m
Comprehensive jet cross section measurements are presented, spanning the dijet mass range from 70 GeV to 5 TeV. In addition, event shapes constructed from jets are measured, as well as measurements of jets containing charm and beauty hadrons. These measurements constitute precision tests of QCD in a new energy regime, and show sensitivity to the parton densities in the proton and to the value of the strong coupling, alpha_s. The internal structure of jets is important at the LHC both as a test of perturbative QCD and as a tool for identifying boosted electroweak-scale objects decaying to hadrons. Detailed measurements of jet fragmentation, of subjet variables, single jet masses and jet shapes are presented and compared to the predictions of QCD.
Speaker: Mr Bertrand Chapleau (McGill University (CA))
• 14:45
Jet Measurements in CMS 15m
We present studies of the substructure in multijet and V+jets events at CMS. Several jet grooming techniques are investigated, and We present measurements of jet properties and jet production rates at CMS with pp collisions at 7 TeV. Inclusive jet and dijet differential cross sections are compared to NLO QCD predictions with various PDF sets. We also present studies of the jet substructure in QCD multijet and V+jets events. Several jet grooming techniques are investigated, and predictions from MC generators are compared to collision data .
Speaker: Mr Sanmay Ganguly (Tata Institute of Fundamental Research)
• 15:00
Particle production in DIS at HERA 15m
Scaled momentum distributions for the strange hadrons K0s and Lambda/Lambdabar were measured in deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 330 pb-1. The evolution of these distributions with the photon virtuality, Q2, was studied in the kinematic region 10 < Q2 < 40000 GeV2 and 0.001 < x < 0.75, where x is the Bjorken scaling variable. Clear scaling violations are observed. Predictions based on different approaches to fragmentation were compared to the measurements. Tuned leading-logarithm parton-shower Monte Carlo calculations interfaced to the Lund string fragmentation model describe the data reasonably well in the whole range measured. Next-to-leading-order QCD calculations based on fragmentation functions, FFs, extracted from e+e- data alone,fail to describe the measurements. The calculations based on FFs extracted from a global analysis including e+e-, ep and p$data give an improved description. The measurements presented in this paper have the potential to further constrain the FFs of quarks, anti-quarks and gluons yielding K0s and Lambda/Lambdabar strange hadrons. The production of neutral strange particles is studied at low Q2, using deep-inelastic scattering events recorded with the H1 Detector at HERA. The production cross sections are presented differentially as a function of several kinematical variables in the laboratory and the Breit frame. Moreover, the strangeness production rate is compared to the equivalent rate of charged particles in a similar phase space. The H1 data are compared to theoretical predictions, based on leading order Monte Carlo programs with matched parton showers, with different values of the strangeness suppression factor. The electron-proton collider HERA allows deep-inelastic scattering (DIS) at very small Bjorken-x of about 10^-5. At such small x new parton dynamics beyond DGLAP are expected to become important. Charged particle spectra are measured in DIS (Q^2 > 5 GeV^2), in different regions of pseudorapidity, using the increased statistics of HERA-2. The measurements are compared to simulations based on different Monte Carlo generators. It is shown that the region of small transverse momenta is primarily sensitive to hadronisation, whereas the region of large transverse momenta is mainly driven by perturbative parton radiation. The observed hardness of the transverse momentum spectra, when compared to different model predictions, can be interpreted as supporting the idea of parton dynamics beyond DGLAP. The production of photons at very small angles with respect to the proton beam direction is studied in deep-inelastic positron-proton scattering at HERA. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of 126 pb−1. The analysis covers the range of negative four momentum transfer squared at the positron vertex 6 < Q2 < 100 GeV2 and inelasticity 0.05 < y < 0.6. Cross sections are measured for the most energetic photon with pseudorapidity η > 7.9 as a function of its transverse momentum p_T^lead and longitudinal momentum fraction of the incoming proton x_L^lead. In addition, the cross sections are studied as a function of the sum of the longitudinal momentum fraction x_L^sum of all photons in the pseudorapidity range η > 7.9. The cross sections are normalised to the inclusive deep-inelastic scattering cross section and compared to the predictions of models of deep-inelastic scattering and models of the hadronic interactions of high energy cosmic rays. Speaker: Dr Anastasia Grebenyuk (DESY (DE)) • 15:15 The Energy Dependence of the Underlying Event in Hadron-Hadron Collisions 15m We study the behavior of the underlying event in proton-antiproton collisions at 300 GeV, 900 GeV, and 1.96 TeV using charged particles measured by the CDF detector. The charged particle density and the scalar PTsum density in the transverse region as defined by the leading charged particle, PTmax, are examined as a function of PTmax at the three center-of-mass energies. The data at 300 GeV and 900 GeV were taken just before the shutdown of the Tevatron. The 900 GeV results are compared directly with similar studies at the LHC and combining Tevatron and LHC results allows for a mapping out of the energy dependence of the underlying event at 300 GeV, 900 GeV, 1.96 TeV, and 7 TeV. We also examine the ability of the QCD Monte-Carlo models to simultaneously describe the behavior of the underlying event at all four center-of-mass energies. Speaker: Prof. Richard Dryden Field (University of Florida (US)) • 15:30 Refreshment Break 30m • 16:00 Multi-jet matching of parton showers to NLO 15m LHC is now entering a precision era. No striking signals of new phenomena have yet been found, and the searches now have to focus on very small deviations from the Standard Model. This requires an unprecedented precision in our understanding of the Standard Model. Even though the experiments are extremely ingenious in finding model-independent ways of determining the background, this is not always possible and they have to rely event generators. And even if model-independent determinations are possible, they typically need precise event generators to be developed and understood. During the last years, much effort has gone into increasing the precision of event generators by carefully matching or merging parton shower programs with exact fixed-order matrix elements. The merging of tree-level matrix elements has now become the standard for multi-jet events, but this leading order procedures lacks in precision. For many processes the matching of Next-to-Leading Order (NLO) matrix elements with parton showers has become state-of-the-art, but the standard programs can only handle the lowest possible jet-multiplicities. In this talk I will briefly review the standard matching and merging procedures, and then present a new algorithm where multi-jet NLO matrix elements can be correctly merged with parton showers. The new algorithm has been implemented in the Pythia8 event generator and will in principle be able to handle any process where multi-jet partonic states can be produced to NLO, however, in this talk I will only present results for W+jets and Higgs+jets observables. Speaker: Prof. Leif Ingvar Lönnblad (Lund University (SE)) • 16:15 NLO Vector+Jets Predictions with BlackHat & Sherpa 15m Calculations to next-to-leading order in QCD of Standard-Model processes provide the leading quantitatively reliable predictions. They are a prerequisite for comparisons to experimental data. The BlackHat collaboration has been pushing the high-multiplicity frontier in such calculations. In this talk, representing the BlackHat collaboration, I present the next-to-leading predictions for W and Z production in association with three and four jets at the LHC, results for W production in association with five jets; and results for pure four-jet production. I also show comparisons to available Atlas and CMS data. Speaker: Dr David Kosower (CEA - Centre d'Etudes de Saclay (FR)) • 16:30 Interplay of IR-Improved DGLAP-CS Theory and NLO Parton Shower MC Precision 15m We present the interplay between the new IR-improved DGLAP-CS theory and the precision of NLO parton shower/ME matched MCs as it is realized by the new MC Herwiri1.031 in interface to MC@NLO. We discuss phenomenological implications using comparisons with recent LHC data on single heavy gauge boson production. Speaker: Prof. Bennie Ward (Baylor University (US)) • 16:45 MBR Monte Carlo Simulation in PYTHIA8 15m We present the MBR (Minimum Bias Rockefeller) Monte Carlo simulation of (anti)proton-proton interactions and its implementation in the PYTHIA8 event generator. We discuss the total, elastic, and total-inelastic cross sections, and three contributions from diffraction dissociation processes that contribute to the latter: single diffraction, double diffraction, and central diffraction or double-Pomeron exchange. The event generation follows a renormalized-Regge-theory model, successfully tested using CDF data. Based on the MBR-enhanced PYTHIA8 simulation, we present cross-section predictions for the LHC and beyond, up to collision energies of 50 TeV. Speaker: Dr Robert Ciesielski (Rockefeller University (US)) • 17:00 A rigorous assessment of intrinsic accuracies and uncertainties of NLO+PS matching methods 15m Similarities and differences between the MC@NLO and the POWHEG methods for matching NLO calculations to parton showers are discussed. Particular emphasis is put on their respective formal accuracies. Implementations of both methods in the SHERPA event generator framework are employed to assess their impact on representative observables. Some freedoms in both formulations will be exploited to quantify the uncertainties for different processes of interest. Further, NLO+PS matched results for complex final states, e.g. the production of a W boson in association with up to 3 jets or a Higgs boson with up to 1 jets will be presented. Speaker: Dr Marek Schoenherr (University of Durham (UK)) • 17:15 NLO Assistance to LHC Searches with Complex Final States using BlackHat and Sherpa 15m The prediction of backgrounds to new physics signals in topologies with large missing transverse energy and jets is important to new physics searches at the LHC. The BlackHat collaboration has investigated theoretical issues in extrapolating backgrounds from experimental control regions to signal regions. For example, we compute, ratios of gamma + n-jet to Z + n-jet production rates and kinematic distributions in NLO QCD, and compare with a parton shower matched to leading-order matrix elements. These predictions validate uncertainty estimates used by CMS for the irreducible Z + n-jet component of MET+jets searches. We also describe the phenomenon of left-handed W polarization at large transverse momentum, its theoretical prediction and recent measurement by CMS and ATLAS, and its potential role in background separation. Speaker: Prof. Lance Dixon (SLAC National Accelerator Laboratory (US)) • 17:30 . 30m • 09:00 18:00 TR 8 - Neutrinos RM 219 Room 217 ### Room 217 #### Melbourne Convention and Exhibition Centre Melbourne Australia • 09:00 Status and plans with the GERDA experiment to probe the nature of neutrinos 15m Neutrinoless double-beta decay (DBD) could answer the key question regarding the Majorana or Dirac nature of neutrinos and give an answer to the unknown absolute mass scale as well as on the neutrino mass hierarchy. High-Purity Germanium (HPGe) detectors are extremely sensitive tools for the search of neutrinoless DBD. This is demonstrated by the GERDA (GERmanium Detector Array) experiment that is currently searching for the DBD of Ge-76 at the Gran Sasso underground Laboratory of INFN, Italy. In its first phase it will scrutinize the claim of observation of neutrinoless DBD in Ge-76 made by a part of the Heidelberg-Moscow Collaboration. The GERDA experiment is designed to minimize the background by operating HPGe detectors directly immersed in ultra-pure cryogenic liquid. The GERDA physics run started in November 2011 using about 15 kg HPGe detectors isotopically enriched in Ge-76. The status of the data taking and the most relevant results will be presented. The spectrum of the neutrino-accompanied DBD of Ge-76 has been observed with unprecedented signal-to-background ratio. A new measurement of the half-life of the neutrino-accompanied DBD of Ge-76 will be given. For the second phase of GERDA additional ~20 kg of Broad Energy Germanium (BEGe) detectors with favorable properties for improved background recognition are being produced from material enriched in Ge-76. First BEGe detectors with superior energy resolution (1.7 keV at 1.3 MeV)have already been produced and have been characterized. The status of the preparations and further plans for GERDA phase II data taking will be presented. Speaker: Dr Bela Majorovits (Max-Planck-Institut für Physik (DE)) • 09:15 Status of the Cuore experiment at Gran Sasso 15m Cuore (Cryogenic Underground Observatory for Rare Events) is a second generation neutrino-less double beta decay experiment whose sensitivity is expected to be in the range of 41-95 meV for the electron neutrino effective mass. In Cuore the decay of 9.6 10**26 Te-130 nuclei (206 kg) is observed by means of 988 TeO2 crystals acting as bolometers at very low temperature (~10 mK). The experiment is located at the Laboratori Nazionali del Gran Sasso in Italy and is now approaching the final stage of construction. Most of the crystals have been produced, and the final test of the Cuore assembly line (so called Cuore-0 test) is expected to be up and running by June 2012. If successful, the construction of the full Cuore detector will begin in summer 2012 and is expected to finish by 2014. The talk will summarize the physics reach of the experiment, the status of the construction, and the expected sensitivity. Speaker: Dr Sergio Di Domizio (University of Genoa & INFN (IT)) • 09:30 Search for Neutrinoless Double Beta Decay in Xenon 136 with the Enriched Xenon Observatory (EXO) 15m The EXO collaboration is searching for neutrinoless double beta decay in 136Xe. Observation of this process would establish the Majorana nature of neutrinos and lepton number violation, while determining an absolute mass scale for neutrinos. The EXO-200 detector is a ultra low background TPC, with an active mass of ~100 kg of liquid xenon enriched to 80.6% in the isotope 136. The detector is currently operating at the underground WIPP site in New Mexico, USA and has been collecting data since May 2011. The collaboration has previously reported the first observation of two-neutrino double beta decay in 136Xe. In our new data, no signal is observed for an exposure of 32.5 kg-yr, with a background of ∼1.5 × 10−3 kg−1 yr−1 keV−1 in the ±1 sigma region of interest. This sets a lower limit on the half-life of the neutrinoless double-beta decay T1/2(136Xe) > 1.6 × 1025 yr (90% CL), corresponding to effective Majorana masses of less than 140–380 meV, depending on the matrix element calculation. Current R&D efforts towards a ton-scale experiment will also be discussed. Speaker: Dr Peter C. Rowson (SLAC (US)) • 09:45 Latest results from the NEMO-3 experiment and status of SuperNEMO 15m The NEMO-3 experiment, designed to search for neutrinoless double beta decay, was carried out from 2003 to 2011 in the Modane Underground Laboratory in the Frejus Tunnel. The detector employed thin isotopic foils surrounded by a drift chamber and scintillator blocks to reconstruct topology, energy, and timing features of nuclear decays. This multi-observable technique offers a powerful means not only to identify double beta decays but also to reject background events mostly due to natural radioactivity. NEMO-3 employed seven different isotopes to construct foils, with most notable mass of Mo-100 of 6.9kg and Se-82 of 0.93kg. Data from the entire running period are currently being analyzed but NEMO-3 has already achieved the best-to-date results on half-lives of all seven isotopes and has reported lower limits on neutrinoless double beta half-lives which can be translated to the most stringent upper limit on the effective neutrino mass. The next generation experiment, SuperNEMO, will employ the technique pioneered by NEMO-3 but will ultimately house about 100kg of an isotopic source distributed in 20 detector modules. SuperNEMO's goal is to reach half-life sensitivity of about 10^26 years and thus about 50meV for an upper limit for the effective neutrino mass. The collaboration has conducted an extensive R&D program to improve detector performance and lower backgrounds in the new detector and the construction of the first "demonstrator" module has commenced. The module will be commissioned in 2014 and remaining modules will be built later in the decade. The baseline choice for an isotope is Se-82 but this technique has flexibility to use any other source. The collaboration also considers Ca-48 and Nd-150 if sufficient amounts of these isotopes can be enriched, currently viewed as an extremely challenging task of its own. Speaker: Prof. Karol Lang (University of Texas at Austin (US)) • 10:00 Results from KamLAND-Zen double-beta decay experiment with 136Xe 15m KamLAND-Zen is an experiment for neutrino-less double-beta decay search with 136Xe. A newly constructed balloon was installed inside the current 13m diameter KamLAND balloon and filled with 136Xe loaded liquid scintillator in 2011. The data taking was started in October 2011 and the first physics results were obtained with an exposure of 77.6 days with 129 kg of 136Xe. We measured the two neutrino beta-decay half-life of 136Xe, T1/2(2nu)=2.38 ± 0.02(stat)±0.14(syst)×10^21 yr and obtained an improved lower limit for the neutrino-less double-beta decay half-life, T1/2(0nu) > 5.7×10^24 yr at 90% confidence level. Speaker: Dr Satoru Yamada (Tohoku University (JP)) • 10:15 The KATRIN neutrino mass experiment 15m The KATRIN experiment aims at a direct and model independent determination of the neutrino mass with 200 meV sensitivity (90% C.L.) via a measurement of the endpoint region of the tritium beta-decay spectrum. The main components of the experiment are a windowless gaseous tritium source (WGTS), differential and cryogenic pumping sections and a tandem of a pre- and a main-spectrometer, applying the concept of magnetic adiabatic collimation with an electrostatic retardation potential to analyze the energy of beta decay electrons and to guide electrons passing the filter onto a segmented silicon PIN detector. At present the experiment is being installed at the Karlsruhe Institute of Technology and many components are undergoing extensive testing. In the Tritium Laboratory Karlsruhe the demonstrator of the WGTS has been set up. The differential pumping section DPS2F has been installed and initial tests have been completed. A large range of test experiments and background studies have been performed at the pre-spectrometer. The main spectrometer with its air coil system and inner wire electrode is currently in the process of being closed up for bake-out of the system, after which the commissioning of this major component can take place. The 148 pixel silicon detector, required for spectrometer operation, is in place and currently undergoes a refinement of its readout electronics. The talk will present an overview of the experimental status and give an outlook on the commissioning activities. The project is supported by the german ministry of research and education (BMBF) under contract number 05A11PM2. Speaker: Dr Volker Hannen (University of Münster (DE)) • 10:30 Refreshment Break 30m • 11:00 Double Chooz: new results on the theta_13 mixing angle 15m The Double Chooz experiment presented in November 2011 a first indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. The observed deficit in the neutrino rate, along with the distortion of the neutrino energy spectrum, is interpreted as a consequence of the oscillation driven by the mixing angle theta_13. In 2012, a second analysis has been performed by the Double Chooz collaboration after 250 days of data taking confirming the oscillation effect and providing a more accurate best-fit value for the theta_13 angle. A detailed description of the Double Chooz latest results will be given in the talk. Speaker: Dr Pau Novella Garijo (CIEMAT (ES)) • 11:15 First Results of the Daya Bay Reactor Neutrino Experiment 15m The neutrino mixing angle θ13 is the gateway of studying CP violation in lepton sectors and determines the trend of future neutrino experiments. The Daya Bay Reactor Neutrino Experiment aims to precisely determine θ13, with the design sensitivity better than 0.01 in sin^22θ13 at the 90% C.L. The experiment takes a near-far relative measurement by comparing the observed electron-antineutrino rates and spectra at various baselines from the reactors. Functionally identical antineutrino detectors are deployed in water pools underground, in order to minimize the systematic errors and to suppress the cosmogenic backgrounds. The experiment started physics data taking on Dec.24, 2011. An overview of the experiment and the results using data up to May.15, 2012 will be presented. Speaker: Dr Liangjian Wen (Institute of High Energy Physics (CN)) • 11:30 MINOS neutrino oscillation results 15m The MINOS experiment finished data collection in April this year. We have made precision measurements of the oscillation parameters using both neutrino (10.7e20pot) and anti-neutrino (3.3e20pot) enhanced beams and with atmospheric neutrinos (37.9 kt.y). The atmospheric neutrino sample can also be separated into neutrino and antineutrino samples with the magnetic field in the far detector. Updated results of measurements in the 23-mixing sector and the sub-dominant 13-mixing sector will be presented including combined fits from beam and atmospheric data to the separate neutrino and antineutrino mixing parameters. The MINOS+ experiment (the MINOS detector in the ME NOVA beam) will commence running in April 2013. Speaker: Dr Giles Barr (Oxford University (UK)) • 11:45 Results from T2K 15m The Tokai to Kamioka (T2K) experiment is a long baseline neutrino oscillation experiment situated in Japan. A high intensity neutrino beam is produced at the Japan Proton Accelerator Research Complex, in Tokai, Japan. A near detector complex, situated 280 m from the neutrino production target, and the far detector at 295 km, are used to detect the neutrinos from this beam. This talk will present T2K results for the neutrino mixing angles θ_{23}, and θ_{13}, using the data collected up to summer 2012. Speaker: Dr Ken Sakashita (KEK (JP)) • 12:00 Measurement of the muon neutrino flux and inclusive charged-current cross-section at T2K's near detector 15m We present the first measurement of the muon neutrino spectrum at the T2K near detector, ND280, using the data collected at the JPARC accelerator facility in Tokai, Japan. ND280 is located 280 meters downstream from the target and 2.5^o off-axis from the direction of the beam. The measured spectrum at ND280 constrains the flux and cross section uncertainties in the T2K oscillation analysis. We select inclusive charged-current (CC) events from muon neutrinos in ND280. These are separated into a charged current quasi elastic (CCQE) enhanced sample and a CC non-QE sample. We then fit the muon spectrum for both samples to extract flux and cross section parameters which are used as inputs into T2K's oscillation analysis. We separately produce a flux-averaged differential inclusive CC cross-section in the 2-dimensional plane of muon momentum and angle. For the cross-section measurement the flux is given by the MC and tuned to data from the NA61 experiment. We present the event selection, detector uncertainties, and final measurement result for both the spectrum measurement and for the cross-section result. Speaker: Ms Melody Ravonel (University of Geneva (CH)) • 12:15 Measurement of NC pi0 production and CC interactions using the ND280 P0D. 15m The T2K experiment is a long baseline neutrino oscillation experiment designed for the primary goal of measuring oscillations of muon neutrinos to electron neutrinos, thereby providing an appearance measurement of theta_13. One of the major backgrounds of the electron neutrino appearance measurement is from neutral current muon neutrino interactions where a single neutral pion is produced and the photons from the pi-zero decay mimic the electron neutrino appearance signal. To constrain the uncertainty on this background the T2K near detector facility at 280 meters from the proton beam target was used to measure neutral current pi-zero production by muon neutrinos. Presented is a measurement of the neutral current single pi-zero production cross section using 8.55 times 10^19 protons-on-target (POT) of T2K data. We also report the status of an ongoing analysis to measure charged-current interactions in the P0D in which the momentum of the muon is measured in the downstream TPC. Speaker: Dr Glenn Lopez (Stony Brook University (US)) • 12:30 Neutrino cross section measurements at MINERvA 15m MINERvA (Main INjector Experiment for v-A) is a neutrino scattering experiment, employing a fine-grained detector with an eight ton active target region, located in the NuMI high-intensity neutrino beam at the Fermi National Accelerator Laboratory. MINERvA was designed to make precision measurements of low energy neutrino and antinuetrino cross sections on a variety of different materials (plastic scintillator, C, Fe, Pb, He and H2O). The experiment will provide important inputs, both in support of neutrino oscillation searches and as a pure weak probe of the nuclear medium. We present the current status of the analyses of the charge current quasi-elastic scattering in plastic scintillator, for both the neutrinos and antineutrinos. In addition We present the current status of the charge current inclusive analyses in the plastic scintillator and in the nuclear targets of carbon, iron and lead. Speaker: Mr Rick Snider (Fermi National Accelerator Laboratory (US)) • 12:45 Lunch Break 1h 15m • 14:00 Recent Cross Section Measurements from MiniBooNE 15m A precise knowledge of the neutrino cross sections at ~1 GeV on nuclear targets is required to determine the remaining neutrino oscillation parameters accurately. Until recently, our knowledge of neutrino interactions was based on measurements from 20-year old bubble chamber experiments on hydrogen and deuterium targets. As a result, the systematic uncertainties due to neutrino cross sections are large. In order to reduce these uncertainties neutrino oscillation experiments had to constrain and measure the cross sections. The MiniBooNE experiment at Fermilab was a short baseline neutrino oscillation experiment designed to confirm or refute the LSND signal. MiniBooNE has collected the largest sample of neutrino and anti-neutrino interactions in the ~1 GeV region. The latest neutrino cross section results from MiniBooNE are presented. Speaker: Dr Heather Ray (University of Florida (US)) • 14:15 Model independent determination of the axial mass parameter in quasielastic neutrino-nucleon scattering 15m Quasielastic neutrino-nucleon scattering is a basic signal process for neutrino oscillation studies. At accelerator energies, the corresponding cross section is subject to significant uncertainty due to the poorly constrained axial-vector form factor of the nucleon. A model-independent description of the axial-vector form factor is presented. Data from the MiniBooNE experiment for quasielastic neutrino scattering on carbon are analyzed under the assumption of a definite nuclear model. The value of the axial mass parameter, m_A=0.85^{+0.22}_{-0.07} +/- 0.09 GeV, is found to differ significantly from extractions based on traditional form factor models. Implications for future neutrino scattering and pion electroproduction measurements are discussed. Speaker: Prof. Richard Hill (University of Chicago (US)) • 14:30 The ArgoNeuT and MicroBooNE Experiments at Fermi National Accelerator Laboratory 15m Liquid argon time projection chambers provide an extraordinary level of information about the interactions of neutrinos. There are several different efforts ongoing at Fermi National Accelerator Laboratory to develop the liquid argon detector technology and utilize it to study neutrino interactions. Among these are the Argon Neutrino Teststand, or ArgoNeuT, project and the MicroBooNE experiment. ArgoNeuT deployed a relatively small, 170 liter, detector in the NuMI neutrino beamline at Fermilab, and the data collected during that endeavor is now being analyzed and used to measure neutrino interaction cross-sections. MicroBooNE is beginning construction this year of a 100 ton liquid argon detector which will be installed in the Booster neutrino beamline at Fermilab and used to measure a wide variety of cross-sections as well as probing the low-energy excess previously reported by the MiniBooNE experiment. This talk will include discussion of recent results and ongoing analyses from ArgoNeuT, as well as the status of the MicroBooNE experiment and its planned physics program. Speaker: Prof. Mitchell Soderberg (Syracuse University (US)) • 14:45 Short baseline neutrino and anti-neutrino oscillation studies at the CERN-SPS. 15m The possibility of mixing between standard active neutrinos and neutrino fields which are singlets under the gauge symmetries of the Standard Model was proposed a long time ago. Recent tensions between world-wide experimental data renewed the possibility of at least a sterile neutrino state to explain the observations. While a huge effort is being devoted to resolve the standard three-neutrino mixing paradigm at present no resolutive experimental setup was carried out or proposed to unambiguosly settle these anomalies. Here we present the proposal for an experimental search for sterile neutrinos with a new CERN-SPS neutrino beam using muon spectrometers and large LAr detectors. To definitively clarify the physics issue the proposed experiment will study oscillations in a muon neutrino/antineutrino beam both in appearance and disappearance modes in the eV2 square mass difference region. Speaker: Prof. Maximiliano Sioli (INFN (IT)) • 15:00 New results of the OPERA long-baseline experiment in the CNGS neutrino beam 15m The OPERA neutrino experiment is placed in the CERN Neutrino beam to Gran Sasso (CNGS), 730 km from the beam source at CERN, in the underground Gran Sasso Laboratory. With the aim to measure the neutrino velocity on this baseline with higher accuracy than previous studies using accelerator neutrinos, dedicated upgrades of the CNGS timing system and of the OPERA detector were undertaken, as well as a high precision geodesy campaign to assess the neutrino baseline. With data taken by OPERA from 2009 to 2011, they led to preliminary results in 2011, updated in May 2012. Further verifications and up-to-date results on the neutrino velocity using special short bunch beams will be presented. Speaker: Prof. Maximiliano Sioli (INFN (IT)) • 15:30 LAGUNA-LBNO: a very long baseline neutrino oscillation experiment 15m LAGUNA (Large Apparatus for Grand Unification and Neutrino Astrophysics)-LBNO(Long-Baseline Neutrino Oscillation)* is the proposal for a long baseline neutrino oscillation experiment with a new conventional neutrino beam aimed at a next generation deep-underground neutrino observatory composed of a double phase liquid Argon detector and a magnetized iron calorimeter located at the Pyhsalami mine, 2300 km from CERN. The design of experimental apparatus is mainly driven by the successful phase of of R&D and prototyping on small scale setups: i) higher signal efficiency along with high background rejection are attainable with the double phase LAr LEM TPC tracking-calorimeter technology thanks to the three-dimensional mm-scale spatial resolution and the excellent energy resolution capabilities. ii) the detector will be complemented with a magnetized calorimeter for the muon detection in order to improve the reconstruction of events occurring in the LAr target. The Phyasalmi mine, the deepest in Europe (4000 m.w.e.), represents a unique experimental location to observe new rare phenomena, both accelerator and non-accelerator based. An unprecedented rich physics program can be pursued. i) neutrino oscillations can be studied in detail fully exploiting, for the first time, the energy spectrum information of the oscillation probability (L/E method) in appearance and disappearance mode at long baseline. An exposure of 2.25x10^20 protons on target (p.o.t.) from the CERN SPS at 400 GeV would allow for a definitive determination (> 5 sigma C.L.) of the neutrino mass hierarchy for any value of the CP violation phase delta_CP. The CP violation can be instead discovered at 3 sigma, through the L/E method, with a coverage of the 70% of the delta_CP parameter space, providing 1.5x10^21 p.o.t., which is achievable possibly in 10 years of exposure. ii) Grand Unified Theories (GUT) can be investigated with searches for several nucleon decay signatures and with unprecedented sensitivities thanks to the very large detector mass and the extremely clean cosmological background. iii) atmospheric neutrinos, as well as unknown astrophysical neutrinos (e.g. from D.M. annihilation) can be studied for the first time over a wide range of energies and final states iv) the explosion of a galactic Supernova (SN) will be detected with large statistics, in neutrino and antineutrino modes and in all flavors allowing to constrain both the astrophysics of the SN and the neutrino flavor oscillations. Main achievements of the R&D phase will be illustrated along with the future plan. The status of the LAGUNA-LBNO project proposal will be discussed along with the possible realization schedules. It will be highlighted the physics reach of a CERN-Pyhasalmi long baseline conventional beam coupled to one or more experiment(s), based on an incremental approach, initially starting from the existing CERN SPS performance and far detector(s) with mass ranges in the 20 kton-scale, and gradually increasing the far detector masses and/or the SPS beam power. * European Commission Framework Programme 7 Design Study LAGUNA (Project Number 212343). Speaker: Dr Silvestro Di Luise (ETH-Zurich Institute for Particle Physics (CH)) • 15:45 Refreshment Break 15m • 16:00 The search for CP violation and the determination of the neutrino mass hierarchy in NOnuA and LBNE 15m With the recent discovery of a non-zero value of the neutrino mixing angle$\theta_{13}$, the NuMI Off-Axis$\nu_e$Appearance (NO$\nu$A) long baseline neutrino oscillation experiment, currently under construction, has unique sensitivity to both the CP-violating neutrino mixing phase and the neutrino mass-hierarchy. Beyond NO$\nu$A, the proposed Long-Baseline Neutrino Experiment (LBNE) is designed for much greater sensitity to the CP-violating phase while providing a very rich physics program. I will review the design, capabilities and schedule of both experiments. Speaker: Dr Jonathan Paley (Argonne National Laboratory (US)) • 16:15 The Hyper-Kamiokande Experiment 15m We propose the Hyper-Kamiokande (Hyper-K) detector as a next generation underground water Cherenkov detector. It will serve as a far detector of a long baseline neutrino oscillation experiment envisioned for the upgraded J-PARC, and as a detector capable of observing -- far beyond the sensitivity of the Super-Kamiokande (Super-K) detector -- proton decays, atmospheric neutrinos, and neutrinos from astronomical origins. The baseline design of Hyper-K is based on the highly successful Super-K, taking full advantage of a well-proven technology. Hyper-K consists of two cylindrical tanks lying side-by-side, the outer dimensions of each tank being 48 m (W) x 54 m (H) x 250 m (L). The total (fiducial) mass of the detector is 0.99 (0.56) million metric tons, which is about 20 (25) times larger than that of Super-K. A proposed location for Hyper-K is about 8 km south of Super-K (and 295 km away from J-PARC) at an underground depth of 1,750 meters water equivalent (m.w.e.). The inner detector region of the Hyper-K detector is viewed by 99,000 20-inch PMTs, corresponding to the PMT density of 20% photo-cathode coverage (one half of that of Super-K). Hyper-K presents the potential for determination of the CP phase$\delta$in the 3-flavor framework and therefore has discovery reach for CP violation in the lepton sector. With a total exposure of 5 years (one year being equal to 10$^7$sec) to a 2.5 degree off-axis neutrino beam produced by the 1.66 MW J-PARC proton synchrotron, it is expected that the CP phase$\delta$can be determined to better than 18 degrees for all possible$\delta$values of and CP violation can be established with a statistical significance of 3$\sigma$for 70% of the$\delta$parameter space assuming the recent measured$\theta_{13}$by T2K, Daya Bay, and RENO, and a known mass hierarchy. The mass hierarchy itself can be determined with more than 3$\sigma$statistical significance for 46% of the$\delta$parameter space. Furthermore, Hyper-K’s high statistics data sample of atmospheric neutrinos will allow us to extract additional information on the mass hierarchy and the octant of$\theta_{23}$. With a full 10 year duration of data taking, the significance for the mass hierarchy determination is expected to reach 3$\sigma$or greater if$sin^2\theta_{23} > 0.4$. Hyper-K will extend the sensitivity to nucleon decays beyond what can be achieved by Super-K by an order of magnitude or more. The sensitivities to the partial lifetime of protons for the decay modes p →$e^+ \pi^0$and p→$\var{\nu}K^+$are expected to exceed 1x$10^{35}$years and 2x$10&^{34}$years, respectively. This is the only known, realistic detector option capable of reaching such a sensitivity for the p→$e^+\pi^0$mode. The scope of studies at Hyper-K also covers high precision measurements of solar neutrinos, observation of both supernova burst neutrinos and supernova relic neutrinos, and dark matter searches. Speaker: Dr Hiroyuki Sekiya (Kamioka Observatory ICRR University of Tokyo) • 16:30 CP Violation at a Neutrino Factory 15m Exciting prospects for the discovery of CP violation in the neutrino sector have recently been made more likely by the measurement of the neutrino mixing angle theta_13. CP violation is a necessary condition for leptogenesis to be at the origin of the matter-antimatter asymmetry of the universe. A number of future options for establishing CP violation in neutrinos are possible, but the Neutrino Factory, in which beams of neutrinos are created from the decays of muons in a storage ring, offers the best sensitivity for this discovery and the most precise measurements of the mixing parameters and CP phase in the leptonic sector, which is related to the problem of flavour, the existence of three generations in nature and leptogenesis. The International Design Study for the Neutrino Factory (the IDS-NF) was established to deliver a Reference Design Report (RDR). The baseline design has been revised in the light of the new theta_13 results. The facility will provide 10^21 muon decays per year from 10 GeV stored muon beams pointing at a large (100 kton) Magnetised Iron Neutrino Detector (MIND) at a distance between 2000—2500 km. A description of the facility and a new upgraded neutrino oscillation analysis will be used to determine the CP sensitivities and the measurement of the CP phase delta. A compelling case for a Neutrino Factory will be made, based on the unprecedented precision in delta and the prospects of new physics in the neutrino sector that such a Neutrino Factory will be able to establish. Speaker: Prof. Kenneth Long (Imperial College London (UK)) • 16:45 Getting the best out of T2K and NOvA 15m Neutrino oscillation physics stands at an important juncture today. With the reactor experiments having measured a moderately large value of$\theta_{13}$, determination of the neutrino mass hierarchy and$\delta_{CP}$are the next problems to be solved. In this work, we explore the physics potential of T2K and NOvA, with the aim of extracting as much physics as possible from them before the next generation of experiments. At these baselines, the hierarchy-$\delta_{CP}$degeneracy makes it difficult to measure the hierarchy independently of$\delta_{CP}$. For hierarchy determination, we find that the lower half plane (LHP) of$\delta_{CP}$is favourable for NH and the upper half plane (UHP) is favourable for IH. If the favourable combinations (NH,LHP) or (IH,UHP) occur, then NOvA by itself can determine the hierarchy. If$\delta_{CP}$lies in the unfavourable half plane, NOvA allows a large region with wrong hierarchy. Combined data from the planned runs of NOvA and T2K cannot determine the hierarchy even for the large$\theta_{13}$. However, the situation improves dramatically with a moderate increase in statistics. We demonstrate that the hierarchy can essentially be determined, even for unfavourable values of$\delta_{CP}$, if the exposures of NOvA and T2K are increased by a factor of 1.5 and 2 respectively. We find that addition of another experiment with a baseline of 130 km and beam power equivalent to T2K leads to a marginal improvement. It would seem that an experiment with a shorter baseline (and hence small matter effects) like T2K may be able to measure$\delta_{CP}$without knowing the hierarchy. We show that this is not the case. No matter how small the matter effects, for some value of$\delta_{CP}$, any single experiment gives a wrong hierarchy-wrong$\delta_{CP}$solution. However, combined data from 2*T2K+1.5*NOvA can determine the correct half plane of$\delta_{CP}$. Speaker: Mr Suprabh Prakash (Indian Institute of Technology - Bombay (IN)) • 17:00 The Neutrino Flavour Puzzle in the Light of Large Theta_13 15m What is the origin of the observed fermion masses and mixing parameters? Neutrinos, with their small mass and large mixing, contribute an important part of this flavour puzzle. We discuss new developments regarding the flavour puzzle in the light of the recent discovery of comparatively large leptonic mixing theta_13. The new developments include the possibility to explain the observed value of theta_13 from charged lepton corrections in Grand Unified Theories, a new type of Constrained Sequential Dominance models leading to tri-maximal mixing with predicted theta_13 and unsuppressed CP asymmetries for leptogenesis, as well as a new class of models with predicted CP violation in the quark and lepton sectors. Speaker: Prof. Stefan Antusch (University of Basel (CH)) • 17:15 Large \theta_{13} from minimal SO(10) unification 15m Unified theories based on SO(10) are ideal settings to address the masses and mixings of neutrinos. In minimal SO(10) models there are just two Yukawa coupling matrices, one associated with a 10 and one with a 126 of Higgs bosons (as opposed to five such matrices in the standard model). This results in a predictive framework for the neutrinos: all neutrino mixing angles and mass ratios can be computed in terms of the quark and lepton mass parameters. Even though quarks and leptons are unified, large neutrino mxing angles emerge simultaneously with small quark mixing angles. The prediction for the reactor neutrino mixing angle is \sin^2 (2\theta_{13}) = (0.08 - 0.095), which is nicely consistent with recent results from Daya Bay and RENO experiments. This talk will present the minimal model and its predictions, including the expectations for the neutrino CP violation paramter \delta. A new mechanism that connects neutrino masses with the baryon asymmetry of the universe will be presented, which relies on the B-L violating decays of GUT scale scalars. Speaker: Prof. Kaladi S. Babu (Oklahoma State University (US)) • 17:30 The Simplest Neutrino Mass Matrix Revisited 15m In 2004, two of us published a texture, the `Simplest'' neutrino mass matrix, which predicted$\sin{\theta_{13}}=\sqrt{2\Delta m^2_{sol}/3\Delta m^2_{atm}}$and large$\delta_{CP}$. Using today's measured values for neutrino mass-squared differences, this prediction gives$\sin^2\! 2{\theta_{13}}\simeq 0.086^{+0.003}_{-0.006}$, compared with a measured value, found by averaging the results of the Daya Bay and RENO experiments, of$\sin^2\! 2{\theta_{13}}=0.097\pm0.012$. Here, we develop that texture separately for the cases of Dirac and Majorana neutrinos. For Dirac neutrinos, we use the measured value of$\theta_{13}$to predict the lightest neutrino mass. For the Majorana case, we present a specific model underlying this successful texture, and we explore its phenomenology in the context of the See-saw mechanism. Large$CP$-violation is a generic prediction of the texture. Speaker: Prof. Paul Fraser Harrison (University of Warwick (UK)) • 17:45 Renormalization Group Running of Physical Parameters in Neutrino Models and Extra Dimensions 15m In this talk, we investigate renomalization group running of neutrino parameters such as neutrino masses and leptonic parameters in different models. The models range from the inverse seesaw model to radiative versions of the scotogenic model as well as extra-dimensional models with both one and two extra spatial dimensions. We find that most models lead to large running for theta_12, whereas the running is negligible for theta_13 and theta_23. In addition, we show that a bimaximal mixing pattern at high energies (e.g. at the GUT scale) can lead to non-zero values for theta_13 at low energies. Finally, using the running of the Higgs self-coupling constant, we derive bounds on the cutoff scale for one of the extra-dimensional models. Speaker: Prof. Tommy Ohlsson (KTH Royal Institute of Technology (SE)) • 09:00 18:00 TR2 - Plenary 3 - Beyond the Standard Model - SUSY Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia • 09:00 NLO corrections to squark-squark production and decay at the LHC 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre We present the analysis of the signature jj+missing-ET(+X) via squark-squark production and direct decay into the lightest neutralino in next-to-leading order QCD within the framework of the minimal supersymmetric Standard Model. We provide a consistent, fully differential calculation of NLO QCD factorizable corrections to the given processes with on-shell squarks. Clustering final states into partonic jets, we investigate the experimental inclusive signature jj+missing-ET and we choose for illustration several benchmark scenarios. We compare resulting differential distributions with leading-order approximation rescaled by a flat K-factor and examine a possible impact for cut-and-count searches for supersymmetry at the LHC. Speaker: Mr Davide Pagani (Max-Planck-Institut für Physik (DE)) • 09:15 Gluino pair production at threshold 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre We present a next-to-leading order calculation for the production of gluino pairs near threshold at the LHC. We show that threshold effects lead to a characteristic shape of the differential cross section around threshold and an increase of the total cross section. Speaker: Dr Peter Marquard (KIT (DE)) • 09:30 Inclusive searches for squarks and gluinos with the ATLAS detector 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia Despite the absence of experimental evidence, weak scale supersymmetry remains one of the best motivated and studied Standard Model extensions. This talk summarises recent results on inclusive searches for supersymmetric squarks and gluinos in events containing jets, missing transverse momentum with or without leptons. The searches use the full data sample recorded in 2011 at sqrt(s)=7 TeV centre-of-mass energy by the ATLAS experiment at the LHC. Results using a sqrt(s)=8 TeV data sample from the 2012 run may also be presented. Speaker: Mr Moritz Backes (Universite de Geneve (CH)) • 09:45 Searches for SUSY in hadronic final states at CMS 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia We present results of searches for SUSY production at CMS in events containing hadronic jets and missing energy. Various discriminants based on the event kinematics are employed to suppress standard-model backgrounds. The results are interpreted in the context of the Constrained Minimal Supersymmetric Standard Model, and of a number of "simplified models". Speaker: Dr Seema Sharma (Fermi National Accelerator Lab. (US)) • 10:00 Searches for SUSY in final states with single leptons at CMS 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia We search for evidence of Supersymmetry in events with a single lepton, multijets and missing energy. The search is done with proton-proton collision data collected by the CMS detector at the CERN Large Hadron Collider. The backgrounds, which are primarily from W+jet and top quark production, are predicted with control samples in the data. The results are interpreted in terms of the constrained minimal supersymmetric extension of the standard model as well as more generic Simplified Model Spectra (SMS) topologies. Speaker: Prof. Kajari Mazumdar (Tata Institute of Fundamental Research) • 10:15 Searches for SUSY in events with two or more leptons at CMS 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia We present results of searches for SUSY production at CMS in events with multiple lepton production. These include final states with Z bosons decaying to lepton pairs, non-resonant same- and opposite-sign lepton pairs, and three or more isolated leptons. The results are used to exclude previously unexplored regions of the supersymmetric parameter space assuming R-parity conservation with the lightest supersymmetric particle being either a neutralino or gravitino. Speaker: Dr Pablo Martinez Ruiz Del Arbol (Eidgenoessische Tech. Hochschule Zuerich (CH)) • 10:30 Refreshment Break 30m Plenary 3 (Melbourne Convention and Exhibition Centre) ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia • 11:00 Search for Pair Production of the Scalar Top Quark in Mu+Tau Final States 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia We present a search for the pair production of scalar top quarks (stop_1), the lightest supersymmetric partners of the top quarks, in ppbar collisions at a center-of-mass energy of 1.96 TeV, using data corresponding to an integrated luminosity of 7.3 fb^-1 collected with the D0 experiment at the Fermilab Tevatron Collider. Each scalar top quark is assumed to decay into a b quark, a charged lepton, and a scalar neutrino (snu). We investigate final states arising from stop_1 \bar{stop_1} --> b\bar{b}\mu\tau snu snu and stop_1 \bar{stop_1} --> b\bar{b}\tau\tau snu snu. With no significant excess of events observed above the background expected from the standard model, we set exclusion limits on this production process in the (m_{stop_1},m_{snu}) plane. Speaker: Dr James Alexander Kraus (Michigan State University (US)) • 11:15 Searches for direct pair production of third generation squarks with the ATLAS detector 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses not too far from those of their Standard Model counterparts. Scalar top or bottom quarks with masses less than a few hundred GeV can give rise to direct pair production rates at the LHC that can be observed in the data sample recorded by the ATLAS detector. The talk presents results from searches for direct stop and sbottom production using a data sample recorded in 2011 at sqrt(s)=7 TeV centre-of-mass energy by the ATLAS experiment at the LHC. Speaker: Dr Martin John White (University of Melbourne (AU)) • 11:30 Searches for SUSY in events with third-generation particles at CMS 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia We present results of searches for SUSY production at CMS in events with third-generation signatures. Along with missing energy, the final states may include hadronic jets with or without b-quark tag, light leptons, and tau leptons. These features serve both to distinguish standard-model components, and for sensitivity to those SUSY models that lead to final states rich in heavy-flavored particles. Speaker: Dr Altan Cakir (Deutsches Elektronen-Synchrotron (DE)) • 11:45 Searches for supersymmetry in events with photons or tau leptons and missing transverse momentum with the ATLAS detector 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia Models with gauge-mediated supersymmetry breaking predict that the lightest supersymmetric particle is a gravitino with negligible mass so that the phenomenology of the supersymmetric events produced at the LHC is determined by the next-to-lightest supersymmetric particle (NLSP). Depending on the model parameters, the NLSP can be a neutralino with significant bino admixture that will decay into a photon, or a stau that will decay into a tau lepton. The talk presents results from searches for supersymmetry in events with photons or taus and missing transverse momentum, using the data sample recorded in 2011 at sqrt(s)=7 TeV centre-of-mass energy by the ATLAS experiment at the LHC. Speaker: Mr Steffen Schaepe (Universität Bonn (DE)) • 12:00 Search for Z+photon events with Large Missing Transverse Energy in ppbar Collisions at 1.96 TeV 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia We present the first search for supersymmetry (SUSY) in Zgamma final states with large missing transverse energy using data corresponding to an integrated luminosity of 6.2 fb-1 collected with the D0 experiment in ppbar collisions at sqrt(s)=1.96 TeV. This signature is predicted in gauge-mediated SUSY-breaking models, where the lightest neutralino is the next-to-lightest supersymmetric particle (NLSP) and is produced in pairs, possibly through decay from heavier supersymmetric particles. The NLSP can decay either to a Z boson or a photon and an associated gravitino that escapes detection. We exclude this model at the 95% C.L. for SUSY breaking scales of Lambda < 87 TeV, corresponding to neutralino masses of < 151 GeV. Speaker: Dr James Alexander Kraus (Michigan State University (US)) • 12:15 Searches for SUSY in final states with photons at CMS 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia We present results of searches for SUSY production at CMS in events with one or two isolated photons. The results are interpreted in terms of guage-mediation models, with the gravitino as the lightest supersymmetric particle. Speaker: Prof. Mike Hildreth (University of Notre Dame (US)) • 12:30 New results using the razor at the LHC 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia The "razor" at the LHC refers to a set of kinematical variables used to discriminate heavy new physics against standard model processes. The empirical modeling of the variables and their correlation leads to good sensitivity to new physics. In this talk we present some of the latest results obtained with the razor technique in CMS, ranging from SUSY to more exotic searches. Speaker: Dr Will Reece (CERN (CH)) • 12:45 Lunch Break 1h 15m Plenary 3 (Melbourne Convention and Exhibition Centre) ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia • 14:00 Interpretations of CMS SUSY analyses in the simplified model space (SMS) 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia This talk we will present a compilation of all CMS new physics search results in the simplified model space and discuss the advantages and limitations of such interpretations. Speaker: Mr Christopher Rogan (California Institute of Technology (US)) • 14:15 Constrained Supersymmetry after two years of LHC data: a global view with Fittino 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia We perform global fits to the parameters of the Constrained Minimal Supersymmetric Standard Model (CMSSM) and to a variant with non-universal Higgs masses (NUHM1). In addition to constraints from low-energy precision observables and the cosmological dark matter density, we take into account the LHC exclusions from searches in jets plus missing transverse energy signatures with about 5\,fb$^{-1}$of integrated luminosity. We also include the most recent upper bound on the branching ratio$B_s\to\mu\mu$from LHCb. Furthermore, constraints from and implications for direct and indirect dark matter searches are discussed. The best fit of the CMSSM prefers a light Higgs boson just above the experimentally excluded mass. We find that the description of the low-energy observables,$(g-2)_{\mu}$in particular, and the non-observation of SUSY at the LHC become more and more incompatible within the CMSSM. A potential SM-like Higgs boson with mass around 126 GeV can barely be accommodated. Values for${\cal B}(B_s\to\mu\mu)$just around the Standard Model prediction are naturally expected in the best fit region. The most-preferred region is not yet affected by limits on direct WIMP searches, but the next generation of experiments will probe this region. Finally, we discuss implications from fine-tuning for the best fit regions. Speaker: Dr Xavier Prudent (Technische Universität Dresden) • 14:30 SUSY fits: Implications of LHC data on Constrained SUSY Models 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia We present the latest results of the MasterCode collaboration on global SUSY fits. Currently available experimental data are used to determine the preferred SUSY and Higgs boson mass scales. The data comprise a combination of high-energy SUSY searches, low-energy precision measurements and astrophysical data. We include all relevant LHC searches for SUSY, electroweak precision observables such as the W boson mass and the anomalous magnetic moment of the muon, B physics observables such as BR(b -> s gamma), as well as the cold dark matter density in the Universe. Speaker: Dr Albert De Roeck (CERN (CH)) • 14:45 Constraints from direct dark matter searches, rare decays and LHC limits on Supersymmetry 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia The direct searches for Superymmetry can be complemented by direct searches for dark matter, if one assumes the Lightest Supersymmetric Particle (LSP) provides the dark matter of the universe. It is shown that within the CMSSM the direct searches are more sensitive than the direct LHC searches for large values of the squark masses, even if one considers the uncertainties from the local relic density and the form factors. A combined excluded region from LHC, rare decays, WMAP and XENON100 are provided, showing that gluinos below 1 TeV are excluded (m1/2 > 400GeV ) independent of the squark masses. This limit implies an LSP mass above 160 GeV in the CMSSM. Speaker: Prof. Dmitry Kazakov (JINR (RU)) • 15:00 Implications of LHC Higgs and SUSY searches for MSSM 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia The implications of a discovery, or a non-discovery, of the lightest Higgs boson will be discussed in terms of constrained and general MSSM scenarios. Exploring the MSSM through the Higgs sector is an alternative and complementary path to direct searches, and tight constraints on the parameter space can be obtained. Such constraints will be discussed in addition to, very briefly, the interplay with other sectors. Speaker: Dr Nazila Mahmoudi (CERN (CH) & Clermont Ferrand University (FR)) • 15:15 Light stop phenomenology 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia We discuss the phenomenology of light scalar tops (stops) in the minimal supersymmetric standard model (MSSM). We analyse the discovery potential of stops in the co--annihilation region at the Large Hadron Collider (LHC). The bino-like neutralino is the lightest supersymmetric particle (LSP) and the lighter stop is the next-to-LSP. Such scenarios can be consistent with electroweak baryogenesis and also with dark matter constraints. Provided, the mass difference between LSP and NLSP is small enough, we exploit the opportunity of a light and long-lived stop. We investigate the prospects to extract supersymmetric couplings from a decay length measurement at the LHC. Finally, we discuss the prospects to test relations of the superpotential. So far, no such tests have been proposed for the LHC. Speaker: Dr Jong Soo Kim (University of Adelaide (AU)) • 15:30 Refreshment Break 30m Plenary 3 (Melbourne Convention and Exhibition Centre) ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia • 16:00 Searches for supersymmetric gaugino production in final states with leptons with the ATLAS detector 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the Higgs and electroweak gauge bosons, so-called gauginos, with masses not too far from those of their Standard Model counterparts. Gauginos with masses less than a few hundred GeV can give rise to direct pair production rates at the LHC that can be observed in the data sample recorded in 2011 by the ATLAS detector. The talk presents results from searches for gaugino production in final states with leptons. Speaker: Mr Tobias Kruker (Universität Bern (CH)) • 16:15 One-loop effects on MSSM parameter determination via chargino production at the LC 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia Very precise measurements of masses and cross sections are expected to be achievable with a future linear collider. With such an accuracy one is even sensitive to quantum correction, which therefore must be incorporated in order to make meaningful predictions for the underlying new physics parameters. For the chargino--neutralino sector, this involves fitting one-loop predictions to expected measurements of the cross section and forward-backward asymmetry for chargino pair production and of the accessible chargino and neutralino masses. We consider three scenarios, each with characteristic features, chosen taking recent LHC SUSY and Higgs searches into account. Our analysis allows the accurate determination of the desired parameters and, additionally, access to the mass of the lighter stop that enters via loop corrections. Speaker: Dr Aoife Bharucha (University of Hamburg (DE)) • 16:30 SUSY prospects for Linear Colliders in view of LHC results 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia We re-evaluate prospects for Supersymmetry at a future Electron Positron Linear Collider in light of the first 5 fb^-1 of data taken at LHC with$\sqrt{s}=7$TeV proton proton collisions. Strong new limits from LHC SUSY searches, along with a hint of a Higgs boson signal around$m_h\sim 125$GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. We present a variety interesting Linear Collider benchmark points in scenarios including: natural SUSY, hidden SUSY, the Kallosh-Linde model, NUHM2 with low$m_A$, as well as the remaining phase space of mSUGRA/CMSSM. While all proposed benchmark points at present elude LHC limits - and some will at least for a long time - they are compatible with electroweak precision and flavour observables and do offer intriguing case studies for a Linear Collider operating at$\sqrt{s} = 0.25-1$TeV. Speaker: Dr Jenny List (DESY (DE)) • 16:45 Exploring Sypersymmetry with future e+e- Linear Colliders 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia Proposed e+e- linear colliders a with center-of-mass energy from 250 GeV to 3 TeV (International Linear Collider, ILC and Compact Linear Collider, CLIC) are ideal tools for exploring supersymmetry, in addition to precision Higgs, top, W and Z physics and more generic searches for BSM phenomena. These machines cover a wide range of possible mass spectra of sparticles from 100 GeV to 1.5 TeV, and can explore the slepton and gaugino sectors as well as colored sparticles accessible by pair production. The excellent measurement performance of linear colliders for masses, spins, couplings, etc. provides the possibility to identify the underlying mechanisms after the discovery of SUSY-like particles. In this presentation we will focus on experimental studies of various SUSY models and particles, mainly with realistic detector simulations of ILD, SiD and CLIC geometries. Speaker: Dr Taikan Suehara (The University of Tokyo (JP)) • 17:00 Searches for supersymmetry in resonance production and R-parity violating signatures with the ATLAS detector 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia An extended QCD sector beyond the minimal supersymmetric standard model or the admission of R-parity violation introduces new signatures to the search for supersymmetry at the LHC. Strongly interacting resonances may decay to jets, sleptons may decay via lepton-flavour violating processes and lightest supersymmetric particles may decay into many leptons with or without missing transverse momentum. The talk presents results from searches for scalar gluons and R-parity violation in dijet and multilepton final states using the full data sample recorded in 2011 at sqrt(s)=7 TeV centre-of-mass energy by the ATLAS experiment. Speaker: Mr Daniel Joseph Pomeroy (Brandeis University (US)) • 17:15 Search for Squarks in R-parity Violating Supersymmetry in ep Collisions at HERA 15m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia A search for squarks in Rparity violating supersymmetry is performed in e^\pm p collisions at HERA using the H1 detector. The full data sample taken at a centre-of-mass energy sqrt(s) = 319 GeV is used for the analysis, corresponding to an integrated luminosity of 255 pb^-1 of e+p and 183 pb^-1 of e^-p collision data. The resonant production of squarks via a Yukawa coupling lambda' is considered, taking into account direct and indirect R-parity violating decay modes. Final states with jets and leptons are investigated. No evidence for squark production is found and mass dependent limits on lambda' are obtained in the framework of the Minimal Supersymmetric Standard Model and in the Minimal Supergravity Model. In the considered part of the parameter space, for a Yukawa coupling of electromagnetic strength lambda' = 0:3, squarks of all flavours are excluded up to masses of 275 GeV at 95% confidence level, with down-type squarks further excluded up to masses of 290 GeV. Speaker: Dr Gerhard Immanuel Brandt (University of Oxford (UK)) • 17:30 . 30m Plenary 3 ### Plenary 3 #### Melbourne Convention and Exhibition Centre Melbourne Australia • 09:00 18:15 TR4 - Top Quark Physics Room 216 ### Room 216 #### Melbourne Convention and Exhibition Centre Melbourne Australia • 09:00 Inclusive top quark pair production cross - section (ATLAS) 15m We present measurements of the production of top quarks in proton - proton collisions at 7 TeV with the ATLAS detector at the Large Hadron Collider. The cross section of pair - produced top quarks is measured in several channels, including the single lepton, dilepton, all hadronic channel, some using information from b-tagging, as well as channels involving tau leptons. Speaker: Mr Frederic Derue (CNRS IN2P3 UPMC LPNHE (FR)) • 09:15 Top quark pair production cross section at CMS 15m Precision measurements are presented of the top-pair production cross section in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV. The data are collected with the CMS experiment during the year 2011. The measurements are performed in several decay channels, the lepton+jets, the dilepton and the fully hadronic channels, including the tau-dilepton and tau+jets modes. B-jet identification is used to increase the purity of the selection. The backgrounds are determined using data-driven techniques. The results are combined with each other and compared with theory predictions. Speaker: Dr Ana Rodriguez Marrero (Universidad de Cantabria (ES)) • 09:30 Differential top quark pair production (ATLAS) 15m After having established the ttbar production mechanism at LHC, interest is now focused on differential spectra of ttbar. Latest measurements performed in 7 TeV proton - proton collisions with the ATLAS detector at the Large Hadron Collider will be presented. Speaker: Dr Taylor Childers (CERN (CH)) • 09:45 Differential cross sections in top pair events at CMS 15m We present measurements of various differential cross sections in top pair production in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV. The data are collected by the CMS experiment during the year 2011. Cross sections are measured differentially as a function of various variables, including the transverse momentum and rapidity of the (anti)top quark and the top-antitop system, as well as multiplicity and transverse momenta of jets produced in addition to the top pair. The cross sections are corrected for detector effects to the level of stable particles. The results are compared with various Monte Carlo models, as well as with theory predictions. The overall consistency of the features of top pair production with expectations from the standard model is investigated. Speaker: Dr Maria Aldaya Martin (Deutsches Elektronen-Synchrotron (DE)) • 10:00 Cross section measurements of top quark production at CDF 15m The cross section for top-quark production, either in pairs through chromo-dynamical mechanisms or in single top-quarks through electro-weak based mechanisms, is a topic of great interest for testing theoretical predictions and constraining standard model parameters, as well as for searching for new physics in the top-quark sector. We present recent measurements of the top-quark pair production cross section in the all-leptonic channel and of the single top-quark production cross sections in the s- and t-channels. The combined s+t-channel single top-quark production cross section is also used to measure the |V_tb| matrix element of the CKM matrix. We also present a measurements of the top-quark pair production cross section and branching ratio in the all-leptonic channel where one of the two leptons defining the decay channel is required to be a reconstructed tau channel. The pair production cross section measurements are using the full CDF Run II sample. Speaker: Mr Matteo Corbo (Fermi National Accelerator Laboratory (US)) • 10:15 NRQCD matching coefficient at next-to-next-to-next-to-leading order 15m We present new results for the matching coefficient between the QCD and the non-relativistic QCD (NRQCD) vector current. The matching coefficient constitutes one of the missing ingredients for a complete NNNLO theory prediction of top-quark pair production at a future linear collider. Furthermore, the matching coefficient is an important building block for the analysis of heavy quarkonia, which will allow for the precise determination of the bottom-quark mass from sum rules. Speaker: Dr Peter Marquard (KIT (DE)) • 10:30 Refreshment Break 30m • 11:00 Measurements of the inclusive cross section and of differential distributions in top quark pair production (D0) 15m We present measurements of the inclusive top quark pair production cross section in various final states including electrons, muons, tau leptons, large missing transverse energy, b-tagged and light flavor jets. We also show measurements of differential distributions of top quarks produced in pairs which provides a unique test of the dynamics of a heavy diquark system at large scales and represents a powerful search for new physics. The measured spectra, binned in several observables, are compared to simulations from different Monte Carlo generators. The measurements use up to 10 fb^-1 of data collected with the D0 detector at the proton-antiproton Tevatron collider at a center-of-mass energy of 1.96 TeV. Speaker: Prof. Christian Schwanenberger (University of Manchester) • 11:15 Measurements of single top quark production (ATLAS) 15m We present the result of measurements of single top - quark production in the t - and Wt - channels at 7 TeV proton - proton collisions with the ATL AS detector at the Large Hadron Collider. Information on the CKM matrix element |Vtb| is extracted from these measurements. Speaker: Mr Philipp Sturm (Bergische Universität Wuppertal (DE)) • 11:30 Single top production in CMS 15m We present measurements of single top quark production, performed using CMS data collected in 2010-2011 at a centre-of-mass energy of 7 TeV. The cross section for the electroweak production of single top quarks is measured in the t-channel using various methods. The combined result is used to place a constraint on the CKM matrix element Vtb. The data sample analyzed allows to study also differential distributions. For the first time, single top production is measured in the tW channel. Speaker: Dr Gabriele Benelli (University of Kansas (US)) • 11:45 Measurements of single top quark production cross sections and |Vtb| in ppbar collisions at sqrt(s)=1.96 TeV (D0 and CDF) 15m We present measurements of production cross sections of single top quarks in ppbar collisions at sqrt(s) = 1.96 TeV using data collected with the CDF and D0 experiments with integrated luminosities of up to 9.7 fb-1. Measurements of the total production cross section and of the t-channel cross section are presented, as well as searches for the s-channel production process. These measurements are also used to extract the Vtb element of the CKM mixing matrix Speaker: Dr Yvonne Peters (University of Göttingen & DESY (DE)) • 12:00 Measurement of the top quark mass (ATLAS) 15m We present measurements of the top - quark mass in proton - proton collisions at 7 TeV with the ATLAS detector at the Large Hadron Collider. The top mass is determined by making use of a two - dimensional template method in the single lepton channel, and a one - dimensional template method in the all - hadronic channel. An indirect extraction of the top - quark mass from the measurement of the cross - section is also presented. Speaker: Dr Giuseppe Salamanna (University of London (UK)) • 12:15 Measurements of the top quark mass (CMS) 15m The mass of the top quark is a fundamental parameter of the Standard Model. Measurements of the top quark mass are presented using data collected by the CMS experiment during the year 2011, in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV. Different reconstruction methods to extract the top quark mass are employed. The results of the various channels are combined and compared to the world average. The top mass is also extracted from the top pair cross section measured at CMS, including a determination of mtop in the MSbar scheme. Speaker: Dr Hartmut Stadie (Hamburg University (DE)) • 12:30 Measurement of the top-antitop mass difference (CMS) 15m A measurement of the difference between the masses of top and anti-top quarks is presented using data collected by the CMS experiment during the year 2011, in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV. Events from the l+jets channel are selected by requiring one lepton and at least four jets in the final state. The measured value is compared with the prediction from the Standard Model, where no difference in mass between the top quark and the antitop quark is expected. Speaker: Mr Gerrit Van Onsem (Vrije Universiteit Brussel (BE)) • 12:45 Lunch Break 1h 15m • 14:00 Top quark mass measurements at CDF 15m The top-quark mass is an important parameter of the standard model. It is used, along with the W boson mass, to constrain the mass of the predicted Higgs boson. We present measurements of the top-quark mass and of the top-antitop mass difference, which tests the CPT symmetry, in the semi-leptonic top-quark pair decay channel using the template method and the full CDF Run II sample. These are currently the world's most precise top mass and mass difference single measurements. Speaker: Dr Hyun Su Lee (Ewha Womans University) • 14:15 Measurement of the top quark mass in ppbar collisions using events with two leptons (D0) 15m The mass of the top quark is a fundamental parameter of the standard model and has to be determined experimentally. The D0 experiment at the Fermilab Tevatron proton-antiproton collider with a centre-of-mass energy of 1.96 TeV has measured the top quark in various channels. We present the most recent measurements of the top quark mass in the dilepton and lepton+jets channels with up to 5.3 fb-1 as well as their combination and give an outlook on the final, most precise measurement of the top quark mass at D0. Speaker: Dr Oleg Brandt (University of Göttingen (DE)) • 14:30 Tevatron and LHC top mass combinations 15m The top quark is the heaviest known elementary particle and its mass is a free parameter of the Standard Model. The CDF and D0 collaborations have previously measured the top quark's mass using the top quark pairs produced at the Tevatron proton-antiproton collider in many decay channels. We present here the combination of all published measurements with an integrated luminosity up to 5.8 fb^-1 using a proper treatment of the uncertainty correlations between different measurements. This combination leads to the most precise top quark mass determination with a relative precision of 0.54%. Speaker: Dr Frederic Deliot (CEA - Centre d'Etudes de Saclay (FR)) • 14:45 Top Precision Studies at Linear Colliders 15m The top quark is the heaviest particle of the Standard Model and, thus, the particle most strongly coupled to the physics of electroweak symmetry breaking. A future linear e+e- collider will be able to make precision measurements of the top quark mass and width, of the detailed QCD physics of the top quark threshold, and of the top quark production and decay asymmetries. Both measurements at the top quark threshold and measurements in continuum production at 500 GeV have been analyzed with detailed full simulation studies performed within the frameworks of the CLIC conceptual design report and the ILC technical design report. Experiments at an e+e- linear collider have the capability of measuring the top quark mass with unprecedented accuracy, below 100 MeV, and making a direct precision measurement of the top quark width. Further, by using all properties of the e+e- environment -- the electroweak production mechanism, the ability for full event reconstruction, the excellent jet energy measurement, and the excellent b and c identification capabilities -- they make it possible to make precision measurements of the weak and electromagnetic couplings of the top quark, quantities that are directly sensitive to composite Higgs and extra-dimensional models of new physics. Speaker: Dr Marcel Vos (Universidad de Valencia (ES)) • 15:00 Spin correlation and W helicity in top quark events with ATLAS 15m n 7 TeV proton - proton collisions at the LHC, pairs of top and anti-top quarks are expected to be mostly produced through gluon fusion, in contrast to production at the Tevatron, where quark annihilation dominates. The ATLAS experiment has now recorded a large number of top quark pairs, allowing this domain to be explored in detail. We present measurements of the spin correlation between top and anti-top quarks. The helicity fractions of W bosons from top quark decays are precisely predicted by the Standard Model and a deviation could reveal the presence of new physics. We also present a measurement of the W helicity fractions from top quark decays in ATLAS. Speaker: Dr Markus Jüngst (CERN) • 15:15 Spin correlations and W helicity in top events with CMS 15m Measurement of the polarisation of W bosons and top anti-top spin correlations in top-quark decays are presented. The analysis makes use of top-pair events in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV using data collected by the CMS experiment during the year 2011. Final states are selected where one of the two W bosons decays into electron-neutrino or muon-neutrino, and the other into quarks. From these events the W-boson helicity fractions and angular asymmetries are extracted. The spin information is extracted from the the angular distributions of the top quark decay products. The results, in agreement with the expectations from the Standard Model, are presented and used to set limits on anomalous contributions to the Wtb vertex. Speaker: Dr Suharyo Sumowidagdo (University of California Riverside (US)) • 15:30 Refreshment Break 30m • 16:00 Spin correlation in ttbar production (D0) 15m We present a measurement of the ratio of events with correlated t and tbar spins to the total number of ttbar events. This ratio f is evaluated using a matrix-element-based approach in events with a single lepton (electron or muon) and at least four jets and in events with two leptons (ee, emu, mumu) and at least two jets. We analyze ppbar collisions data corresponding to an integrated luminosity of 5.3-5.4 fb-1 collected with the D0 detector at the Fermilab Tevatron collider operating at a center of mass energy sqrt(s)=1.96$ TeV. Combining the results of the single lepton and dilepton final states, we find f in agreement with the standard model. In addition, the combination provides evidence for the presence of spin correlation in ttbar events with a significance of more than three standard deviations.
Speaker: Dr Yvonne Peters (University of Göttingen & DESY)
• 16:15
Measurement of top quark properties - electric charge and width (D0) 15m
We present a measurement of the electric charge of the top quark and an improved determination of the total width of the top quark, Gamma_t, using 5.3 fb-1 of integrated luminosity collected by the D0 Collaboration at the Tevatron ppbar Collider. The top quark charge is reconstructed from the top quark decay products in events which have an isolated high-pT charged lepton, large missing transverse momentum, and at least four high-pT jets, at least two of which identified as b-quark jets by a neural network. We exclude the hypothesis that the top quark is an exotic quark of charge −4e/3 at a confidence level greater than six standard deviations and conclude that the observed top quark charge is in good agreement with the standard model value of 2e/3. The total width Gamma_t is extracted from the partial decay width Gamma(t->Wb), obtained from the t-channel single top quark production cross section, and the branching fraction B(t->Wb) measured in ttbar events. For a top mass of 172.5 GeV, the resulting width is Gamma_t = 2.00 +0.47-0.43 GeV which translates to a top-quark lifetime of tau_t = (3.29 +0.90-0.63) 10-25 s.
Speaker: Prof. Christian Schwanenberger (University of Manchester (UK))
• 16:30
Combination of CDF and D0 measurements of the W boson helicity in top quark decays 15m
We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7 – 5.4 fb−1 of ppbar collisions collected during Run II of the Fermilab Tevatron Collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f0) and right-handed (f+) helicities, we find f0 = 0.722 ± 0.081 [± 0.062 (stat.) ± 0.052 (syst.)] and f+ = −0.033 ± 0.046 [± 0.034 (stat.) ± 0.031 (syst.)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f0 = 0.682±0.057 [± 0.035 (stat.)±0.046 (syst.)] and f+ = −0.015±0.035 [± 0.018 (stat.)±0.030 (syst.)]. The results are consistent with standard model expectations.
Speaker: Prof. Erich Ward Varnes (University of Arizona (US))
• 16:45
Other top quark properties in ATLAS 15m
Other properties of top quarks as measured with the ATLAS detector, using pp collisions at a center-of-mass energy of 7 TeV, are presented. In particular the charge of the quark is determined to be +2/3 as predicted by the Standard Model, while an exotic charge is excluded. The cross-section of additional photon radiation in top quark pairs is also measured and presented in this talk.
Speaker: Dr Antonio Limosani (University of Melbourne (AU))
• 17:00
Other top quark properties in CMS 15m
Measurement of top quark properties, such as the top quark charge and the flavour contents in top quark pair events is presented using proton-proton collision data recorded with the CMS Experiment at the LHC at a centre-of-mass energy of 7 TeV. For the measurement of the top quark charge, the top quark pair events are reconstructed in the muon+jets final state and different top quark charge hypotheses (2/3e or -4/3e) are discriminated by use of the charge correlations between high-pT muons from W boson decays and soft muons from B-hadron decays in b jets. A normalised asymmetry of events categorised with a charge of either +2/3 e or −4/3 e is calculated. The fraction of top quarks decaying into a W-boson and a b-quark relative to all top quark decays, R=BR(t->Wb)/Sum(BR(t->Wq)), is determined by counting the jets identified as b-jets, using a model that relies on the b-tagging and mistagging efficiencies. The results are found consistent with SM predictions.
Speaker: Ms Yvonne Küssel (RWTH-Aachen (DE))
• 17:15
Top quark properties at CDF 15m
The top-quark properties are of special interest for testing standard model predictions and for indirect searches for new physics due to the large mass of the top-quark, probing very short distances, and its uniquely short life time, eliminating hadronization complexities. We present recent measurements of the top-quark decay branching ratio, constraining the |V_tb| matrix element of the CKM matrix; of the helicity fractions of the W boson in the top-quark pair deacys in the semi-leptonic channel; of the spin correlation of the top-quark pair in the all-leptonic decay channel; and of the top-quark charge in the all-leptonic decay channel. All measurements are using the full CDF Run II sample.
Speaker: Dr Youngdo Oh (Kyungpook National University (KR))
• 17:30
. 30m
Speaker: MCEC Admin
• 09:00 18:00
TR5 & TR7 - Room 220 - B Physics and CP Violation, etc. Room 220

### Room 220

#### Melbourne Convention and Exhibition Centre

Melbourne Australia
• 09:00
A proposal to solve some puzzles in semileptonic B decays 15m
Some long-standing problems in the experimental data for semileptonic b -> c l nu decay rates have resisted attempts to resolve them, despite substantial efforts. We show that the presence of a relatively large decay rate into radially-excited D-mesons may alleviate several of these tensions simultaneously. In particular, their presence could help explaining the discrepancy between model calculations and experimental results for the first orbitally-excited doublets, known as the “1/2 vs. 3/2 puzzle”. In order to substantiate our hypothesis, we estimate the decay rate into the first two radially excited charmed states using a quark-model and light-cone sum-rules, finding that it is not unreasonable to expect O(1%) branching fraction for these decays.
Speaker: Mr Florian Bernlochner (University of Victoria (CA))
• 09:15
D+ Purely Leptonic and D0 Semi-leptonic Decays at BESIII 15m
With the world largest data sample taken at psi(3770) peak with the BESIII detector at the BEPCII e+e- collider, the D+ purely leptonic and D0 semi-leptonic decays are studied. We present the preliminary branching fraction measurements of D+ -> mu nu, D0 -> K- e+ nu and D0 -> pi- e+ nu. We extract pseudoscalar decay constant of f_D using D+ purely leptonic decays and the hadronic form factors using the D0 semi-leptonic decays.
Speaker: Prof. Ronald Poling (University of Minnesota (US))
• 09:30
Kaon Physics at CERN: recent results from the NA48/2 experiment 15m
Semileptonic kaon decays offer the most precise determination of the CKM matrix element |Vus|. The experimental precision is however limited by the knowledge of the form factors of this decay, since these enter both the phase space integral and the detector acceptances. The NA48/2 experiment presents new high precision measurements of the form factors of the semileptonic decays of charged kaons (K+- -> pi0 l+- nu), based on 4.3 million Ke3 and 3.5 million Kmu3 decays, both with negligible background. The result matches the precision of the current world average on the vector and scalar form factors and allows to significantly reduce the form factor uncertainty on |Vus|. In addition, the comparison of both channels sets tight constraints on lepton flavour violation and other possible new physics. The NA48/2 collaboration has also accumulated ~60000 semi-leptonic K charged decays Ke4(00) to pi0 pi0 e neutrino, increasing the world available statistics by several orders of magnitude. Background contamination below the percent percent level and very good pi0 reconstruction allow the first accurate measurement of the Branching Fraction and decay Form Factor at the percent level. The achieved precision makes possible the observation of small effects such as pi+ pi- to pi0 pi0 re-scattering below the 2 m(pi+) threshold. Concurrently, more than one million K charged decays Ke4(+-) to pi+ pi- e neutrino has been analyzed, leading to an improved determination of the Branching Fraction by a factor of 3 and detailed Form Factor studies. Both Ke4 modes decay properties bring new precise inputs to Low Energy QCD studies and can provide strong tests of ChPT predictions. While the above analyses are close to completion and should appear shortly with final results, future prospects include the observation of several 1000 decays in similar muonic modes Kmu4(00) (never observed) and Kmu4(+-) (7 events observed). Such poorly known modes could be studied also in the forthcoming NA62 experiment currently under construction.
Speaker: Dr Cristina Biino (Universita e INFN (IT))
• 09:45
Leptonic and semileptonic B decays with tau at BaBar 15m
Within the standard model, the decay B+ --> tau+ nu has the largest branching fraction of any leptonic B decay, yet its reconstruction is made complicated by the multiple final-state neutrinos. The study of this decay is made possible by the ability to reconstruct the other B in the event, unique to the e+e- environment of the B factories. We present the result of an improved analysis using the full BABAR dataset, where the other B is tagged with a large number of hadronic decays. We observe evidence for B+ --> tau+ nu at more than 3 standard deviations, and discuss the implied constraints on models of new physics. The exclusive semileptonic transitions b -->c tau nubar are sensitive to physics beyond the standard model. For example, in type-II two-Higgs-doublet models, the B -->D(*) tau nubar branching fractions are functions of the ratio between tan(beta) and the charged Higgs mass. Using the full BABAR data set, we present measurements of the branching fractions of these decays, normalized relative to those of the decays B -->D(*) l nubar, where l is an electron or a muon. The measurements are performed using a reconstructed D (*) and an electron, muon, or tau recoiling against a fully-reconstructed B meson, taking advantage of the clean B-factory environment and high luminosity. The branching-fraction ratios are extracted from a simultaneous two-dimensional fit to the measured lepton spectrum and the reconstructed missing mass squared. The experimentally challenging background contributions from decays involving D** states are estimated using a control sample. We report the first observation of the semileptonic B --> D tau nubar decay and discuss implications of our results for scenarios of physics beyond the standard model.
Speaker: Dr Guglielmo De Nardo (Napoli University and INFN (IT))
• 10:00
Leptonic and semileptonic B decays at Belle 15m
We present a measurement of the decay $B\to\tau\nu$ using the full Belle data set including $772 \times 10^6$ $B\bar{B}$ collected at the KEKB asymmetric-energy $e^+e^-$ collider. The $B\bar B$ pair events are tagged by fully reconstructing one B meson decaying in a hadronic mode and detecting the $B\to\tau\nu$ candidate in the recoil. We obtain the branching fraction for $B\to\tau\nu$ and present a direct determination of the product of the B meson decay constant $f_B$ and the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{ub}|$. The resulting constraints on the charged Higgs boson are also discussed.
Speaker: Mr Youngmin Yook (Yonsei University)
• 10:15
Charmless semileptonic B decays at BaBar 15m
The q^2 dependence of exclusive semileptonic form factors may be used to test standard-model theoretical calculations, and the total branching fractions provide a measure of the CKM matrix element V_ub. We report on measurements of the differential branching fractions of the exclusive semileptonic decays B-->pi l nubar, B-->eta l nubar, B-->eta’ l nubar, and B-->omega l nubar as a function of q^2. We report the branching fractions for these decays and determine |V_ub| using theoretical predictions from sum-rule and unquenched-lattice QCD calculations. We report a comprehensive study of the partial branching fractions for inclusive b --> u l nbar transitions using decays recoiling against a fully reconstructed B meson performed with the full BABAR data sample. The partial branching fractions are measured in seven overlapping regions of phase space using different kinematic cuts to suppress the much more abundant b --> c l nubar decays. Values of the CKM element |V_{ub}| are determined using four independent calculations of the partial decay rates. The most precise result is obtained from a two-dimensional fit to the m_X vs. q^2 distributions, with no kinematic restriction other than requiring the lepton momentum to be greater than 1 GeV. Furthermore, we report a new limit on weak annihilation, studied using the isospin conjugated decays of the neutral and charged B mesons.
Speaker: Prof. Abner Soffer (Tel Aviv University (IL))
• 10:30
Semileptonic B/Bs decays at Belle 15m
We present a search for the four-body semileptonic baryonic decay $B^-\to p\bar p\ell^-\bar\nu_\ell$ ($\ell=e,\ \mu$) based on a data sample of 772 million $B\bar B$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy electron-positron collider. In this study, a new neural-network based hadronic $B$-meson tagging method is applied. The theoretical expectation of the decay branching fraction is $\sim 1\times 10^{-4}$, which is within the experimental sensitivity of this search.
Speaker: Mr Christian Oswald (Universität Bonn)
• 10:45
Refreshment Break 15m
• 11:00
Tetraquark interpretation of the charged Bottomonium-like states $Z_b^\pm(10610)$ and $Z_b^\pm(10650)$ and implications 15m
We present a tetraquark interpretation of the charged bottomonium-like states $Z^\pm_b(10610)$ and $Z^\pm_b(10650)$, observed by the Belle collaboration in the $\pi^\pm \Upsilon(nS)$ $(n=1,2,3)$ and $\pi^\pm h_b(mP)$ $(m=1,2)$ invariant mass spectra from the data taken near the peak of the $\Upsilon(5S)$. In this framework, the underlying processes involve the production and decays of a vector tetraquark $Y_b(10890)$, $e^+e^- \to Y_b(10890) \to [Z_b^\pm (10610)\pi^\mp, Z_b^\pm (10650)\pi^\mp]$ followed by the decays $[Z_b^\pm (10610), Z_b^\pm (10650)] \to \pi^\pm \Upsilon(nS), \pi^\pm h_b(mP)$. Combining the contributions from the meson loops and an effective Hamiltonian, we are able to reproduce the observed masses of the $Z_b^\pm (10610)$ and $Z_b^\pm (10650)$. The analysis presented here is in agreement with the Belle data and provides crucial tests of the tetraquark hypothesis. We also calculate the corresponding meson loop effects in the charm sector and find them dynamically suppressed.The charged charmonium-like states $Z_c^\pm(3752)$ and $Z_c^\pm(3882)$ can be searched for in the decays of the $J^{PC}=1^{--}$ tetraquark state $Y(4260)$ via $Y(4260) \to Z_c^\pm(3752)\pi^\mp$ and $Y(4260) \to Z_c^\pm(3882)\pi^\mp$, with the subsequent decays $(Z_c^\pm(3752),Z_c^\pm(3882)) \to (J/\psi, h_c)\pi^\pm$.
Speaker: Dr Wei Wang (DESY (DE))
• 11:15
Study of dimuon final states in the decay of B and Y mesons. 15m
We present the observation of a narrow mass state decaying into Y(1s)+photon, where the Y(1s) is detected by its decay into a pair of oppositely charged muons and the photon is identified through its conversion into an electron-positron pair. The significance of this observation is 5.6 standard deviation. The mass of the state is centered at 10.551+/-0.014(stat)+/-0.017 GeV, which is consistent with that of the state recently observed by the ATLAS Collaboration. We also present an update of the search for the decay B0s-->mu+mu- using the full D0 data sample of about 10.4 fb-1 of integrated luminosity. In this analysis, backgrounds have been significantly reduced compared to earlier D0 measurements by addition isolation variables, by reconstructing additional vertices near the B0s decay vertex and by employing multivariate techniques to discriminate between signal and background.
Speaker: Dr Claus Buszello (Uppsala University)
• 11:30
Results on Bottom Baryons with the CDF II Detector 15m
We present the latest results on the search for excited bottom baryon states Lambda_b* in proton-antiproton collisions with a center of mass energy of 1.96 TeV. Using a 10/fb data sample, we study the Lambda_b* resonance states in the Lambda_b0 pi+ pi- decay mode in events collected by the CDF II detector with a displaced vertex trigger.
Speaker: Dr Igor Gorelov (University of New Mexico (US))
• 11:45
Measurement of mass and lifetime of B-hadrons at ATLAS 15m
Using data collected in 2011, the ATLAS Collaboration has measured the lifetime and mass of the Lambda_b, the lifetimes and masses of the B_d and B_s mesons, and the average lifetime for inclusive B production at 7 TeV center of mass energy in proton-proton collisions. The mass ot the Lambda_b is measured with the precision above the world average. Polarization measurements of the Lambda_b are planned.
Speaker: Dr Konstantin Toms (University of New Mexico (US))
• 12:00
Studies of exotic charmonium and bottomonium states with the CMS experiment 15m
CMS has searched for exotic charmonium states in the data sample collected in proton-proton collisions at 7 TeV in 2011. The X(3872) state is reconstructed in the J/psi pi+ pi- decay channel and the production cross-section is computed by determining the ratio to psi(2S) production in the same decay channel. For the first time, prompt and non-prompt contributions to the X(3872) cross section are disentangled by looking at secondary vertices. Furthermore, we also report on searches for other exotic quarkonium states.
Speaker: Keith Ulmer (University of Colorado at Boulder (US))
• 12:15
Heavy flavour spectroscopy at LHCb 15m
LHCb is a dedicated B physics experiment at the LHC. During the 2011 run the experiment collected 1.0 fb-1 of data. This large data sample allows to explore the b baryon sector with unprecedented precision. We will present the first observation of the Λb* baryons and measurements of the properties of Ξb and Ωb baryons. In addition we will present results on the production and properties of the Bc meson, including searches for previously unobserved decay modes.
Speaker: Mr Raphael Märki (Ecole Polytechnique Federale de Lausanne (CH))
• 12:30
Lunch Break 1h 15m
• 13:45
Decays and spectroscopy at Y(1S,2S) at Belle 15m
Using samples of 102 million $\Upsilon(1S)$ and 158 million $\Upsilon(2S)$ events collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider, we study hadronic exclusive decays of these two bottomonium resonances to the three-body final states $\phi KK$, $\omega \pi\pi$ and $K^{\ast 0}(892) K^- \pi^+ + {\rm c.c.}$, as well as two-body processes including the Vector--Tensor ($\phi f_2'(1525)$, $\omega f_2(1270)$, $\rho a_2(1320)$, $K^{\ast 0}(892) \bar{K}_2^{\ast 0}(1430)+{\rm c.c.}$) and Axial-vector--Pseudoscalar ($K_1(1270)^+ K^-+{\rm c.c.}$, $K_1(1400)^+ K^- +{\rm c.c.}$, $b_1(1235)^+ \pi^-+{\rm c.c.}$) modes. Branching fractions are determined for processes with a statistical significance greater than $3\sigma$; otherwise, the upper limits on the branching fractions are set at 90% confidence level. The ratios of the branching fractions of $\Upsilon(2S)$ and $\Upsilon(1S)$ decay into the same final state are used to test the perturbative QCD prediction. The hadronic decays of the narrow $\Upsilon (nS)$ resonances ($n={}$1, 2, or 3) produce large numbers of $u\bar{u}\$, $d\bar{d}$, and $s\bar{s}$ pairs concentrated in a limited phase-space volume, which makes them ideal for searching for multiquark states with non-zero strangeness. Here we report on high sensitivity searches for inclusive production of the predicted $S=-2$ pentaquark baryon $\Xi^{--}$ and six-quark $H$ dibaryon using the 102 million event $\Upsilon (1S)$ and 158 million event $\Upsilon (2S)$ data samples collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The $\Xi^{--}$ search concentrates on the $\Xi\rightarrow \Xi^-\pi^-$ decay mode and has a branching fraction sensitivity at the $10^{-5}$ level; the $H$-dibaryon search includes the $H\rightarrow\Xi^- p$, $\Lambda\Lambda$ and $\Lambda p\pi^-$ decay channels with branching fraction sensitivities approaching $10^{-6}$. Decay branching fractions and momentum distributions for topologically similar inclusive processes $\Upsilon(nS)\rightarrow\Xi^0(1530)X$ and $\Xi_c^0 X$ are measured for the first time. Using samples of 102 million $\Upsilon(1S)$ and 158 million $\Upsilon(2S)$ events collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider, we search for the first time for double charmonium decays from $\chi_{bJ}$, $\Upsilon(1S)$ and $\Upsilon(2S)$ states. No significant signal is observed in these modes and the upper limits on the decay rates are obtained at the 90% confidence level. These limits are consistent with calculations using the NRQCD factorization approach. Using samples of 158 million $\Upsilon(2S)$ events collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider, we study the hadronic exclusive decays of $\Upsilon(1,2S)$ to baryon-antibaryon ($p\bar{p}, \Lambda\bar{\Lambda}, \Sigma\bar{\Sigma},\Xi\bar{\Xi}$) and 0, 1, or 2 mesons ($\pi^0$, $\eta$, and $\pi^{\pm}$). Branching fractions are determined for processes with statistical significance greater than $3\sigma$; otherwise, the upper limits on the branching fractions are set at 90% confidence level. The ratios of the branching fractions of $\Upsilon(2S)$ and $\Upsilon(1S)$ decay into the same final state are used to test the perturbative QCD prediction. The double cascade radiative transitions $\Upsilon(2S) \to \gamma\chi_{bJ}\to \gamma\gamma \Upsilon(1S)$ have been studied using a sample of 158 million $\Upsilon(2S)$ decays recorded with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. These provide the most precise measurement to date of the branching ratios ${\cal B}(\chi_{b0,1,2}(1P) \to \gamma\Upsilon(1S))$ and limits on the total widths of the $\chi_{b}$ states. Results are compared with potential models and recent NRQCD predictions.
Speaker: Dr Matthew Barrett (University of Hawai'i at Manoa)
• 14:00
Charm production and rare charm decays at LHCb 15m
Flavour-changing neutral current decays such as c -> u l+ l– are highly suppressed in the Standard Model (SM), but may be enhanced by New Physics. For D0 -> μ+ μ–, the SM decay rate is dominated by long distance contributions but is still a few order of magnitudes below the current experimental limit. In decays such as D+ -> π+ μ+ μ–, measuring the differential branching ratio as a function of the μ+ μ– invariant mass is a sensitive probe for New Physics contributions. We present results of searches for rare charm decays with the 2011 LHCb data sample, corresponding to an integrated luminosity of 1.0 fb–1.
Speaker: Dr Walter Bonivento (INFN Cagliari (IT))
• 14:15
The charmonium spectroscopy and charmonium decay at BESIII 15m
With the world largest data samples taken at J/psi, psi', and psi'' peaks with the BESIII detector at the BEPCII e+e- collider. The charmonium spectroscopy and charmonium decay dynamics are studied. We report new measurements of the resonant parameters of the spin-singlet states, eta_c, eta_c', and h_c, and their production rates in psi' transitions; we also report observations of many new decay modes of J/psi, psi', chi_cJ, and eta_c, and improved measurements of many existing modes.
Speaker: Prof. Shan Jin (Institute of High Energy Physics)
• 14:30
Charm decays and spectroscopy at BaBar 15m
The flavor-changing neutral-current decays decays D0 --> e+e-, D0 --> mu+mu-, and D0-->gamma gamma are highly suppressed in the standard model, well below observable levels. The decay D0 --> e+mu- is further lepton-flavor violating, and thus can occur only through very slow neutrino mixing. Thus, these decays constitute sensitive probes for possible new-physics contributions. We report new limits on the branching fractions of these decays. The electron and di-photon channels, in particular, benefit greatly from the high photon efficiency and clean environment of the B factory. Charm decays that are very rare or forbidden within the standard model constitute a sensitive search for new physics. We report results of searches for 35 such decays of the D+, D0, D_s , and Lambda_c into final states containing two leptons plus a pion, kaon, or proton. This includes final states involving lepton-number or lepton-flavor violation. We obtain branching-fraction limits of order 10^-6. Most of these are the tightest limits to date, in some cases they are the only results published so far, and some cut into the allowed parameter spaces of published new-physics models. Precision properties of charm mesons help test and provide reference points for many of the tools and approximations used in hadronic calculations, such as lattice QCD computation of hadronic matrix elements. We present a new measurement of the natural line width of the D*+ meson and of the difference between the masses of the D*+ and the D0 mesons. Using the full BABAR dataset, we reconstruct the decays D*+ --> D0 pi+, with the D0 identified in its decays into K-pi+, K-pi+pi-pi+, K-pi+pi0, and Ks pi+pi-.We extract the D*+ width and the pole position in the mass difference Delta m in each sample by fitting the measured $\Delta m$ distribution to the sum of background and signal, modeled as a relativistic P-wave Breit-Wigner line shape convolved with a resolution function. Our results are several times more precise than the previous world average. We report results of measurements of the angular-momentum-excited charmed baryon Lambda_c(2880)+ decaying to Lambda_c+ pi+ pi- using approximatly 316 fb^{-1} of BaBar e+e- collision data. We reconstruct the Lambda_c+ candidates in the decay mode pKpi and measure the Lambda_c(2880)+ mass, width, and production cross section, and study resonances in the Lambda_c+ pi+ pi- final state. We report the first measurements of the relative branching fractions for decays of the Lambda_c(2880)+ into the final states Sigma_c^0(2455) pi+ , Sigma_c^++(2455) pi- , Sigma_c^++(2520) pi- , Sigma_c^0(2520) pi+, and the non-resonant Lambda_c+ pi+ pi- contribution.
Speaker: Dr Romulus Godang (University of South Alabama (US))
• 14:45
Studies of the $\psi(2S)$ and $\psi(3770)$ at KEDR 15m
We present a measurement of the main parameters of the $\psi(2S)$ and $\psi(3770)$ resonances, which has been performed with the KEDR detector at the VEPP-4M $e^{+}e^{-}$ collider. Fitting the energy dependence of the multihadron cross section in the vicinity of the $\psi(2S)$ we obtained the mass value and the product of the electron partial width by the branching fraction into hadrons. These results are significantly precisely than any of the previous experiments. We present a measurement of the mass, total width and electron partial width of the $\psi(3770)$ meson. Interference of resonant and nonresonant $D\overline{D}$ production essential in the near-threshold region has been taken into account. We got two possible solutions for the $\psi(3770)$ electron partial width and the radiatively corrected nonresonant $D\overline{D}$ cross section at the mass of $\psi(3770)$.
Speaker: Mr Korneliy Todyshev (Budker Institute of Nuclear Physics (RU))
• 15:00
Charmonium-like states at BaBar 15m
In the past few years, several new charmonium-like states have been observed above the open-charm threshold, with properties that disfavor their interpretation as conventional charmonium states. It is not clear whether all these states are unique. Specifically, it has been suggested that the X(3915), observed in gamma gamma ->J/psi omega, and the Y(3940), observed in B-->J/psi omega K, may be one and the same as the chi_c2(2P), which was discovered in gamma gamma -> D Dbar. We use the full BABAR dataset to study the process gamma gamma --> J/psi omega. We measure the mass and width of the X(3915) and conduct the first assessment of its spin to determine whether it is the chi_c2(2P) or a new state. We also search for the X(3872), which should be produced in gamma gamma events if it has spin and parity 2+, while the alternative J^P = 1+ assignment would preclude X(3872) production via this mechanism. Di-pion transitions are well known for vector charmonium states. However, they have not been studied for non-vector states, where they may shed light on the nature of some of the new charmonium-like resonances, which are not well understood and whose properties often disfavor interpretation as conventional charmonium. In particular, it has been suggested that the decay X(3872)-->eta_c(1S) pi+ pi- will favor identification of the X(3872) as the eta_c2. In addition, measurement of di-pion transition rates for well-understood charmonium states serves to test charmonium-model predictions. Using two-photon-fusion events, we perform the first search for the decays of the chi_c2(1S), eta_c(2S), X(3872), X(3915), and chi_c2(2P) into the final state eta_c(1S) pi+ pi-, and report limits on the branching fractions for these decays or on the products of the branching fractions and 2-photon widths. In recent years, several new Charmonium-like states have been discovered, which cannot be fully explained by a simple charmonium model. The Y(4260) was discovered by BABAR via its decay into J/psi pi pi. Its production in initial-state-radiation events determines its quantum numbers to be JPC=1--, so the fact that it has not been observed decaying into D* D*bar is in contradiction to the charmonium-model expectation. Other interpretations are also not in good agreement with the data. We use the full BABAR dataset to improve determination of the parameters of the Y(4260) and to study the pi+pi- system, which we find to be predominantly in an S-wave state, with a f0(980) component. We do not confirm the report from Belle of a broad structure around 4.01 GeV. A number of new charmonium-like states have been discovered recently, with properties that disfavor their identification as charmonium states. An understanding of the nature of these states requires precision measurements of their properties. Several of the new states are produced in initial-state-radiation events, indicating the quantum numbers JPC=1--. Of these, the Y(4660) has been observed only in the Belle experiment, and still requires independent confirmation. We report a new study of the final state psi(2S) pi+ pi- in initial-state-radiation events using the entire BABAR dataset. We measure the masses and widths of the Y(4360) and Y(4660), and study the di-pion mass spectrum distributions. Recent discoveries of new charmonium-like states have prompted development of various models to explain them. None of the models, including the standard charmonium interpretation, account well for all the properties of these states. A clear prediction of the 4-quark interpretation is the existence of charged charmonium-like states. Such states are the Z1(4050)+ and Z2(4250)+, which is been reported by Belle to be produced in B-->ZK and to decay into chi_c1 pi+. We search for these states in the decays B0-->chi_c1 pi- K+ and B- -->chi_c1 pi- Ks. We show that adequate treatment of the background requires addressing the angular distribution of the Kpi system, which produces features in the chi_c1 pi+ invariant-mass distribution if not properly handled. Once this is done, we see no evidence for the Z1(4050)+ and Z2(4250)+ states, and set upper limits on the branching fractions of the decays B-->ZK. We also report the total branching fractions of the decays B0-->chi_c1 pi- K+ and B- -->chi_c1 pi- Ks.
Speaker: Dr Valentina Santoro (INFN Ferrara (IT))
• 15:15
Charmonium and exotic particles at Belle 15m
We present the study of narrow charmonium(-like) resonances by $\chi_{c1,c2} \gamma$ final states in $B \to \chi_{c1,c2} \gamma K$ decays at Belle. The results are based on the full $\Upsilon(4S)$ data sample corresponding to $772 \times 10^6\ B\bar B$ pairs recorded by the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. We present the study of $B^{\pm} \to J/\psi\, \eta\, K^{\pm}$ decays at Belle. Along with the branching fraction measurement, we search for narrow charmonium-like resonances in the $J/\psi\, \eta$ final state. The analysis is based on the full $\Upsilon(4S)$ data set corresponding to $772 \times 10^6\ B\bar B$ pairs collected by the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. We present the results of an amplitude analysis of the decay $\bar B^0 \to J/\psi K^- \pi^+$. A search for charged charmonium-like states in the $J/\psi \pi^+$ system has been performed. The analysis is based on a 711 fb${}^{-1}$ data sample collected by the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. The cross section for $e^+ e^- \to J/\psi\, \eta$ between $\sqrt{s}={}$3.8 GeV and 5.3 GeV is measured using 980 fb${}^{-1}$ of data on and off the $\Upsilon(nS)$ resonances collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. Two resonant structures at the $\psi(4040)$ and $\psi(4160)$ are observed in the $J/\psi\, \eta$ invariant mass distribution. The transition rates of $\psi(4040)$ and $\psi(4160)$ to the $J/\psi\, \eta$ final state are measured. This is the first measurement of this hadronic transition mode. No significant signals of the $Y(4008)$, $Y(4260)$, $Y(4360)$, or $Y(4660)$ are observed in the $J/\psi\, \eta$ final state. We search for a doubly charmed tetraquark ($T_{cc}$) using a large data sample collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. Various hadronic models, which are in good agreement in the baryon and meson sectors, show different results for tetraquarks. The production of $T_{cc}$ plays a crucial role for discriminating among these models. We report preliminary results of a search for decays of an exotic state $X$ to various modes with the $\eta_c$ meson: $\eta_c \pi^+ \pi^-$, $\eta_c \omega$, $\eta_c \eta$, and $\eta_c \pi^0$. The analysis is based on a data sample of $772 \times 10^6\ B \bar B$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider.
Speaker: Dr Bruce Yabsley (University of Sydney (AU))
• 15:30
Two-photon collisions at Belle 15m
The invariant mass spectrum of the $\eta' \pi^+ \pi^-$ final state produced in two-photon collisions is obtained using 673 fb$^{-1}$ of data on and off the $\Upsilon(4S)$ collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. The $\eta_c$ mass, width and the product of the two-photon width and the branching fraction of the decay into $\eta' \pi^+ \pi^-$ are measured. We also report the first evidence for the $\eta(1760)$ decays to $\eta' \pi^+\pi^-$. From a fit of the mass spectrum with the coherent $X(1835)$ and $\eta(1760)$ resonances, we set a 90% confidence level upper limit on the product $\Gamma_{\gamma\gamma} {\cal B}$ for the $X(1835)$.
Speaker: Dr Hideyuki Nakazawa (National Central University)
• 15:45
Refreshment Break 15m
• 16:00
The Standard Model confronts CP violation in D^0 -> pi^+ pi^- and D^0 -> K^+ K^- 15m
The recently measured direct CP asymmetries in the processes D^0 -> pi^+ pi^- and D^0 -> K^+ K^- show a significant deviation from the naive Standard Model expectation. Using a general parameterization of the decay amplitudes, we show that the measured branching ratios imply large SU(3) breaking and large violations of the naive 1/N_c counting. Furthermore, rescattering constrains the I=0 amplitudes in the pi pi and K K channels. Combining all this information, we show that, with present errors, the observed asymmetries are marginally compatible with the Standard Model. Improving the experimental accuracy could lead to an indirect signal of new physics.
Speaker: Dr Satoshi Mishima (INFN Rome (IT))
• 16:15
Charm mixing and CP violation at BaBar 15m
 We present a measurement of the D0-antiD0 mixing and CP-violation parameters y_CP and Delta y using the full BABAR dataset. We reconstruct samples of D*-tagged and untagged D0 decays to the final states K+K-, K+/-pi-/+ and pi+pi-. From a simultaneous fit to the different channels, we extract the effective lifetimes of the D0 decaying to the CP-even final states and the flavor-specific final state, and combined them into the mixing parameter y_CP and the CP-violation parameter Delta y. Utilizing the full dataset, new track reconstruction, optimized event selection, and the simultaneous fit to both tagged and untagged samples, we improve both the statistical and the systematic errors with respect to all previous measurements. CP violation in the charm system is predicted to be small, yet evidence for direct CP violation has been reported by the LHCb experiment in 2-body D0 decays. A full understanding of the effect requires CP measurements in multibody decays as well. Using the full BABAR Upsilon(4S) data set, we investigate CP violation in the decay D+ --> K+K-pi+. In addition to the overall decay-rate asymmetry, we present CP violation results using model-dependent and model-independent Dalitz-plot analyses. Recent evidence from LHCb of time integrated asymmetry in 2-body D0 decays motivates further studies of CP violation in the charm-meson system, which is required for a full understanding of the phenomenon. Charm CP-violation studies at the B factories are competitive with LHCb in particular for decay modes that involve neutral particles, and several such measurements have already been performed by BABAR and Belle. We report here new results of time-integrated CP-violation measurements in the decay modes D+ --> Ks K+, D_s --> Ks K+, and D_s --> Ks pi+. Our measurements are the most precise to date, due to very efficient Ks reconstruction and excellent control of systematic errors, including use of a large control sample to reduce the reconstruction asymmetries produced by detector-induced effects. We compare our results with the standard-model prediction, allowing for effects due to K0-K0bar interference.
Speaker: Ms Giulia Casarosa (SLAC & INFN (IT))
• 16:30
Measurements of CP violation in charm decays at CDF 15m
Measurements of CP violation in charm meson decays are presented using the complete 10/fb dataset collected by the CDF experiment at the Tevatron. The difference between CP-violating asymmetries in D0-->K+K- and D0-->pi+pi- decays is observed to be 2.8 sigma different form zero, supporting evidence of CP violation in charm reported by other experiments. In addition, world's most precise measurements of individual asymmetries in D0-->hh and D0->Ks pi pi are reported.
Speaker: Mr Diego Tonelli (CERN (CH))
• 16:45
Studies of charm mixing and CP violation at LHCb 15m
LHCb collected 1.0 fb–1 of data in 2011, corresponding to O(10^8) fully reconstructed decays of open charm hadrons. This data provides unprecedented samples of charmed hadrons, allowing precise measurements of mixing and CP violation parameters. We report the results of searches for mixing and CP violation in 2-body and multi-body decays, with analyses using part or all of the 2011 data.
Speaker: Dr Jordi Garra Tico (University of Cambridge (UK))
• 17:00
Direct CP violation in charm at Belle 15m
We measure the time-integrated rate $R_{WS}$ of the wrong-sign decay $D^0 \to K^+ \pi^- \pi^+ \pi^-$ relative to the Cabibbo-favored right-sign process. The data was recorded with the Belle detector and corresponds to an integrated luminosity of 800 fb${}^{-1}$ at the $\Upsilon(4S)$ resonance. We also report a measurement of the $CP$ asymmetry factor $A_{CP}$ by fitting the $D^0$ and $\bar D^0$ samples separately. We observe evidence for $CP$ violation in the decay $D^+ \to K^0_S \pi^+$ using a data set corresponding to an integrated luminosity of 977 fb${}^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. The $CP$ asymmetry in the decay is measured to be $(-0.363 \pm 0.094 \pm 0.067)\%$, which is 3.2 standard deviations away from zero. This is consistent with the expected $CP$ violation due to neutral kaons in the final state. Using data from the Belle experiment at KEKB asymmetric-energy $e^+ e^-$ collider, we present a measurement of the weak-decay asymmetry parameter $\alpha_{\Lambda_c}$ in the decay $\Lambda_c^+ \to \Lambda \pi^+$. By comparing the results for particle and antiparticle decays, we also present a measurement of the $CP$ violating asymmetry parameter $A_{CP} = (\alpha_{\Lambda_c} \alpha_{\Lambda} - \alpha_{\bar \Lambda_c} \alpha_{\bar \Lambda}) /(\alpha_{\Lambda_c} \alpha_{\Lambda} + \alpha_{\bar \Lambda_c} \alpha_{\bar \Lambda})$. We report preliminary results on the time-integrated $CP$ asymmetry $A_{CP}$ in the decay $D^0 \to \pi^+\pi^-\pi^0$ using a 673 fb$^{-1}$ data sample collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. We set an upper limit on the rate of the Dalitz-distribution-dependent asymmetry between two flavor samples: $D^0$ and $\overline{D^0}$.
Speaker: Mr Byeong Rok Ko (Korea University (KR))
• 17:15
Charm mixing at Belle 15m
We present an updated measurement of the mixing parameter $y_{CP}$ in the decays $D^0 \to K^+ K^-$ and $D^0 \to \pi^+ \pi^-$. The results are obtained from the full data set of 1 ab${}^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. We report a measurement of $D^0 - \bar D^0$ mixing in $D^0 \to K^0_S \pi^+ \pi^-$ decays using a time-dependent Dalitz plot analysis. The results are obtained from a large data sample collected on the $\Upsilon(4S)$ and $\Upsilon(5S)$ resonances with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider.
Speaker: Mr Tao Peng (University of Science & Technology of China)
• 17:30
CP violation in charm decays: Standard Model and Beyond 15m
CP violation in charm decays is studied in light of recent experimental findings of LHCb and CDF.Flavor symmetry violations as manifestly displayed in the data are incorporated without theoretical assumptions. Repercussions for CP asymmetries for some of the B (Bs) -decays are incorporated. Range of expectations from the Standard Model are quantified. Further directions to pursue to isolate potential contributions from new physics are pointed out. This talk is based in part on work done in collaboration with Thorsten Feldman and Soumitra Nandi.
Speaker: Dr Amarjit Soni (Brookhaven National Laboratory (US))
• 17:45
. 15m
• Friday, 6 July
• 09:00 19:30
High School Masterclass Australian Synchotron ()

### Australian Synchotron

• 09:00
High School Masterclass 9h Australian Synchotron

#### Australian Synchotron

• 18:00
Public Lecture 1h The Spot (The University of Melbourne)

### The Spot

#### The University of Melbourne

• 09:00 18:00
Plenary3 - The Standard Model -TR1 Plenary 3

### Plenary 3

#### Melbourne Convention and Exhibition Centre

Melbourne Australia
• 09:00
Precision electroweak measurements at SuperB with polarised beams 15m
SuperB has a programme of precision electroweak measurements made possible using data at the Y(4S) by virtue of beam polarisation. These measurements include sin^2 theta_W obtained via left-right asymmetry measurements of e+e- transitions to pairs of fermions. The precision obtainable at SuperB is expected to match that of the LEP/SLC world average at the center of mass energy of 10.58GeV. Once the Higgs mass is known the SuperB precision electroweak programme will become a search for physics BSM
Speaker: Prof. Michael Roney (University of Victoria (CA))
• 09:15
One-Loop Calculation of the Oblique S Parameter in Higgsless Electroweak Models 15m
If the Higgs boson does not show up soon, we should look for alternative mechanisms of mass generation, satisfying the many experimental constraints which the Standard Model (SM) has successfully fulfilled so far. Following this aim, we present a one-loop calculation of the oblique S parameter within Higgsless models of Electroweak Symmetry Breaking (EWSB) and analyze the phenomenological implications of the available electroweak precision data. Within an effective Lagrangian we implement the chiral symmetry breaking SU(2)_L x SU(2)_R -> SU(2)_(L+R) with Goldstones, gauge bosons and one multiplet of vector and axial-vector massive resonance states. Using the dispersive representation of Peskin and Takeuchi and imposing the short-distance constraints dictated by the operator product expansion, we obtain S at the next-to-leading order in terms of a few resonance parameters. We have found that, in order to match the experimental determination of the S parameter, the resonance masses are required to be over the TeV scale in this kind of strongly-coupled EWSB scenarios.
Speaker: Dr Ignasi Rosell (Universidad CEU Cardenal Herrera and IFIC (ES))
• 09:30
HERWIRI2: Exponentiated Electroweak Corrections in a Hadronic Event Generator 15m
Reaching the desired precision level for W and Z processes at the LHC will require a mixture of higher-order QCD and electroweak corrections. HERWIRI2 is a step in implementing QED x QCD exponentiation in a hadronic event generator. This program implements leading electroweak corrections and coherent exclusive exponentiation in a HERWIG environment. We discuss the status of the program, recent tests, and future developments.
Speaker: Dr Scott Yost (The Citadel (US))
• 09:45
W and Z studies at 8 TeV at CMS 15m
The production of W and Z bosons has been observed in pp collisions at a center-of-mass energy of 8 TeV using data collected in the CMS experiment. W events were selected containing an isolated, energetic electron or muon. Z events were selected containing a pair of isolated, energetic electrons or muons. Data-driven methods are used to estimate reconstruction and triggering efficiencies, and well as the main backgrounds. We present the W and Z signal yields and the extracted cross-sections at sqrt(s)=8 TeV, as well as the ratio of 8 TeV / 7 TeV cross sections.
Speaker: Dr Anna Kropivnitskaya (University of Florida (US))
• 10:00
ATLAS Electroweak measurements from W and Z properties 15m
Precise measurements of W and Z production, including the polarisations of W bosons and of tau leptons produced in W decays are presented. They provide tests of lepton universality and constrain electroweak parameters.
Speaker: Dr Joshua Moss (Ohio State University (US))
• 10:15
ATLAS measurements of W/Z+gamma, searches for new physics and constraints on triple-gauge couplings 15m
Differential and total visible cross sections for W+photon and Z+photon production are measured and compared to the predictions of the standard model. Limits on anomalous triple-gauge couples are derived, and the data are used to search for physics beyond the standard model.
Speaker: Prof. Zhengguo Zhao (Univ. of Science & Tech. of China (CN))
• 10:30
Refreshment Break 30m
• 11:00
Wgamma and Zgamma Production in 7Tev pp collisions 15m
We present the measurement of Wgamma and Zgamma production cross sections using data corresponding to the full 2010 and 2011 periods of the LHC run. For charged lepton decay modes of W and Z bosons the total cross sections are measured for photon transverse energy greater than 15 GeV. We also present the first measurement of Zgamma production cross section using the nunugamma final state for photon transverse energy greater than 145 GeV. The results are also interpreted in terms of limits of anomalous trilinear gauge couplings.
Speaker: Dr Syue-Wei Li (National Central University (TW))
• 11:15
Measurement of W/Z+gamma production and limits on triple gauge couplings in ppbar collisions at sqrt(s)=1.96 TeV 15m
We measure the cross section and differential distributions for the production of a weak bosons (W or Z) in association with a photon in data collected with the D0 detector at the Fermilab Tevatron ppbar collider at sqrt(s)=1.96 TeV and corresponding to integrated luminosities of up to 6.2 fb-1. The W and Z bosons are identified via their leptonic decays to electrons or muons. The results obtained are consistent with the standard model predictions for from next-to-leading order calculations. The differential distributions are used to set limits on possible anomalous couplings in the triple gauge boson vertices.
Speaker: Prof. Heidi Schellman (Northwestern University)
• 11:30
Electroweak corrections to vector-boson pair production at the LHC 15m
W-boson pair production has been studied extensively during the LEP era, amongst others leading to a precise determination of the W-boson mass and width. At the LHC, vector-boson pair production will be of similar importance. Such processes constitute an important irreducible background to SM-Higgs production in the intermediate-mass region and have already been used to exclude a wide range of mass parameters. Moreover, vector-boson pair production is a perfect candidate to probe the non-abelian structure of the SM at highest energies, possibly facilitating the discovery of BSM physics. Therefore, it is obvious that theoretical predictions with high accuracy are needed to benefit from the great experimental possibilities provided by the LHC. In this work, we present the first calculation of the full one-loop electroweak corrections to WW, WZ, and ZZ production at hadron colliders, which give rise to large contributions at high transverse momenta. In addition, photon-induced processes are discussed in detail which contribute significantly to the W-pair production cross section at high invariant masses.
Speaker: Dr Tobias Kasprzik (KIT (DE))
• 11:45
WW, WZ and ZZ production at CMS 15m
We present studies of WW, WZ and ZZ diboson production in pp collisions based on data recorded by the CMS detector at the LHC. These include precise measurements the production cross section of these processes at center-of-mass energies of 7 and 8TeV . The leptonic decay modes of the W and Z bosons are used. The results are interpreted in terms of constraints on anomalous triple gauge couplings. In addition the first observation of the decay Z to 4 charged leptons is reported.
Speaker: Mr Kalanand Mishra (Fermi National Accelerator Lab. (US))
• 12:00
ATLAS measurements of WW, WZ and ZZ 15m
ATLAS measurements of diboson production processes involving ZZ, WW and WZ final states are presented. Differential and total visible cross sections are measured for channels involving leptons and neutrinos, and differential distributions are presented. In the ZZ->2l2nu and WW->lnulnu channels, jet vetos are applied. Total cross sections are derived, and limits are set on anomalous triple-gauge couplings.
Speaker: Dr Chris Hays (University of Oxford (GB))
• 12:15
Measurements of WW and WZ production in W + jets final states in ppbar collisions 15m
We study WW and WZ production with l nu q q (l=e,mu) final states using data collected by the D0 detector at the Fermilab Tevatron Collider corresponding to 4.3 fb-1 of integrated luminosity from ppbar collisions at sqrt(s)=1.96 TeV. Assuming the ratio between the production cross sections sigma(WW) and sigma(WZ) as predicted by the standard model, we measure the total WV (V=W,Z) cross section to be sigma(WV)= 19.6^{+3.2}_{-3.0} pb, and reject the background-only hypothesis at a level of 7.9 standard deviations. We also use b-jet discrimination to separate the WZ component from the dominant WW component. Simultaneously fitting WW and WZ contributions, we measure sigma(WW) = 15.9^{+3.7}_{-3.2} pb and sigma(WZ) = 3.3^{+4.1}_{-3.3} pb, which is consistent with the standard model predictions.
Speaker: Mr Gregorio Bernardi (LPNHE University of Paris (FR))
• 12:30
Lunch Break 1h 30m
• 14:00
Measurement of the WZ/ZZ(Z-->bbbar) Production Cross Section at D0 in ppbar Collisions at sqrt(s)=1.96 TeV 15m
We present a combined measurement of the cross section for the simultaneous production of two vector bosons (WZ,ZZ), where one of the bosons decays leptonically (W-->lv, Z-->ll or Z-->vv) and the other Z boson decays to bbar. The measurement uses the complete Run 2 dataset collected with the D0 detector in ppbar collisions at sqrt(s)=1.96 TeV, and combines the three leptonic decay modes mentioned above. This final state is a direct analog to SM Higgs searches in final states of leptons plus bottom quark pairs, and thus provides a crucial validation benchmark of the Higgs boson signal isolation techniques involved.
Speaker: Dr Bjorn Penning (Fermi National Accelerator Laboratory)
• 14:15
CDF searches for diboson production in final states with heavy flavor jets 15m
We present the results of CDF searches for diboson production in final states with jets identified as originating from heavy flavor quark decays. In particular, searches for WZ/ZZ production where the first W or Z boson decays leptonically and the second Z decays into a pair of bottom or charm quarks mimic primary Tevatron searches for a low mass Higgs with subsequent decay into a pair of bottom quarks produced in association with a W or Z boson. CDF's ability to observe diboson production in these final states provides a critical validation of the tools, techniques, and background modeling used in our H->bb searches.
Speaker: Dr Marco Trovato (Fermi National Accelerator Laboratory (US))
• 14:30
Improved sensitivity to charged Higgs searches un top quark decays $t \to bH^+ \to b(\tau^+\nu_\tau)$ at the LHC using $\tau$ polarisation and multivariate techniques 15m
We present an analysis with improved sensitivity to the light charged Higgs ($m_{H^+} < m_t-m_b$) searches in the top quark decays $t \to b H^+ \to b (\tau^+\nu_\tau) + ~{\rm c.c.}$ in the $t\bar{t}$ and single $t/\bar{t}$ production processes at the LHC. In the Minimal Supersymmetric Standard Model (MSSM), one anticipates the branching ratio ${\cal B} (H^+ \to \tau^+\nu_\tau)\simeq 1$ over almost the entire allowed $\tan \beta$ range. Noting that the $\tau^+$ arising from the decay $H^+ \to \tau^+\nu_\tau$ are predominantly right-polarized, as opposed to the $\tau^+$ from the dominant background $W^+ \to \tau^+\nu_\tau$, which are left-polarized, a number of $H^+/W^+ \to \tau^+\nu_\tau$ discriminators have been proposed and studied in the literature. We consider hadronic decays of the $\tau^\pm$, concentrating on the dominant one-prong decay channel $\tau^\pm \to \rho^\pm \nu_\tau$. The energy and $p_T$ of the charged prongs normalised to the corresponding quantities of the $\rho^\pm$ are convenient variables which serve as $\tau^\pm$ polariser. We use the distributions in these variables and several other kinematic quantities to train a boosted decision tree (BDT). Using the BDT classifier, and a variant of it called BDTD, which makes use of decorrelated variables, we have calculated the BDT(D)-response functions to estimate the signal efficiency vs. the rejection of the background. We argue that this chain of analysis has a high sensitivity to light charged Higgs searches up to a mass of 150 GeV in the decays $t \to b H^+$ (and charge conjugate) at the LHC. For the case of single top production, we also study the transverse mass of the system determined using Lagrange multipliers.
Speaker: Mr Javier Llorente (Universidad Autónoma De Madrid (ES))
• 14:45
Search for charged Higgs bosons decaying via H+->taunu in ttbar events with the ATLAS detector 15m
The results of a search for charged Higgs bosons are presented. The analysis is based on proton-proton collision data recently collected by the ATLAS experiment at the Large Hadron Collider, using ttbar events with a tau lepton in the final state. The data are consistent with the background from Standard Model processes. Assuming branching ratio BR(H+ -> taunu) = 100%, this leads to upper limits on the branching fraction BR(t -> bH+).
Speaker: Dr Aldo Saavedra (University of Sydney (AU))
• 15:00
Search for the Higgs particle in models beyond the MSSM 15m
Results are presented on the search for the non standard-model Higgs production and decays, beyond MSSM SUSY, including the production of a doubly charged Higgs boson decaying onto a pair of like sign charged leptons and a search for a low mass neutral a_0 decaying into a pair of muons. The full data sample of 4.7 fb-1 of pp collisions collected in 2011 with the CMS experiment at a CM energy of 7 TeV have been analyzed, as well as a significant fraction of the 2012 luminosity delivered so far at the new energy of 8 TeV.
Speaker: Prof. James Olsen (Princeton University (US))
• 15:15
Search for Neutral Supersymmetric Higgs Bosons in bbb(b) Final States in ppbar Collisions at sqrt(s)=1.96 TeV 15m
We present a search for Higgs bosons in the bh(h-->bbar) and bbh(h-->bbar) channels at a center-of-mass energy of sqrt(s)=1.96 TeV with the D0 detector at the Fermilab Tevatron collider. In many Supersymmetric models the cross-section for production of neutral Higgs bosons in association with bottom quarks is greatly enhanced compared to the Standard Model, and over much of the parameter space the dominant decay mode is into a pair of bottom quarks. The search is performed in events with 3 and 4 identified b jets and uses the full D0 Run 2 dataset. Currently this search is only performed at the Tevatron and thus provides unique complementary information to searches for Supersymmetric Higgs bosons decaying into tau pairs at the LHC. The sophisticated techniques to model the dominant multijet background, as well as the multivariate techniques used to both efficiently select the signal and suppress the background, will be discussed in detail.
Speaker: Dr Avto Kharchilava (State University of New York (US))
• 15:30
Refreshment Break 30m
• 16:00
Search for Higgs Particles in MSSM SUSY 15m
Results are presented on the search for MSSM SUSY Higgs production and decays, including a neutral Higgs decaying to a pair of tau leptons, and a charged Higgs decaying in tau neutrino. The full data sample of 4.7 fb-1 of pp collisions collected in 2011 with the CMS experiment at a CM energy of 7 TeV have been analyzed, as well as a significant fraction of the 2012 luminosity delivered so far at the new energy of 8 TeV.
Speaker: Dr Christian Veelken (Ecole Polytechnique (FR))
• 16:15
Search for the neutral MSSM Higgs bosons in the H->tautau and H->mumu decay modeswith the ATLAS detector at the LHC 15m
The Minimal Supersymmetric extension of the Standard Model (MSSM) predicts the existence of three neutral and two charged Higgs bosons. The search for the neutral MSSM Higgs bosons in the H-> tau^+ tau^- and H->mu^+mu^- decay modes has been performed using proton-proton collision data recently collected with the ATLAS detector at the Large Hadron Collider. The exclusion limits at the 95% confidence level are discussed as a function of the mA and tan beta parameters .
Speaker: Mr Sascha Ulrich Thoma (Albert-Ludwigs-Universität Freiburg (DE))
• 16:30
Search for a fermiophobic Higgs particle 15m
Vector boson fusion and associate production of Higgs bosons are searched for, with the Higgs decaying into vector bosons. The results are interpreted in a model for a fermiophobic Higgs. The full data sample of 4.7 fb-1 of pp collisions collected in 2011 with the CMS experiment at a CM energy of 7 TeV have been analyzed, as well a significant fraction of the 2012 luminosity delivered so far at the new energy of 8 TeV.
Speaker: Dr Matteo Sani (University of California (US))
• 16:45
Search for Light Higgs Bosons in \Upsilon(1S) and \Upsilon(2S) decays 15m
A light $CP$-odd Higgs boson $(A^0)$ is predicted in some extensions of the Standard Model; such a particle would be evident in decays of the $\Upsilon(nS)$ resonance. Using a data sample of 102 million $\Upsilon(1S)$ events and 158 million $\Upsilon(2S)$ events collected by the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider, we search for light Higgs boson decays $A^0 \to \tau^+ \tau^-$ and $A^0 \to \mu^+ \mu^-$ in the processes $\Upsilon(1S)\to \gamma A^0$ and $\Upsilon(2S) \to \gamma A^0$.
Speaker: Prof. Paoti Chang (National Taiwan University (TW))
• 17:00
Search for light Higgs bosons in radiative Upsilon(1S) decays at BABAR 15m
We search for a light CP-odd Higgs boson (A0) that arises in non-minimal supersymmetric extensions of the Standard Model and naturally couples strongly to bottom quarks. The search is conducted using radiative di-muon and di-tau decays of the Upsilon(1S) meson. We use BABAR’s large data sets of (92.8 +- 0.8) million Upsilon(2S) and (116.8 +- 1.0) million Upsilon(3S) decays to identify Upsilon(1S) production via the decay Upsilon(2S,3S) --> pi+pi- Upsilon(1S). This yields a high-purity sample with a Higgs-search sensitivity similar to that of radiative Upsilon(2S) and Upsilon(3S) decays. We set stringent limits on the product of branching ratios Br(Upsilon(1S) --> gamma A0) x B(A0 --> l+l-) where l = mu or tau, as well as on the effective coupling of the b-quark to the A0. Depending on the parameters of the model, the Higgs may decay predominantly into hadrons. We also present results of a search for a CP-odd Higgs boson produced in radiative Upsilon(2S) or Upsilon(3S) decays and decaying into hadrons. Our results severely restrict the available parameter space for models predicting light Higgs states.
Speaker: Prof. Yury Kolomensky (UC Berkeley & LBNL (US))
• 17:15
Light Higgs Scenario in BMSSM and LEP Precision Data 15m
In this talk we consider very light Higgs fields in BMSSM(Beyond MSSM). The spectrum below TeV scale is the same as the MSSM but the Higgs potential is modified and is well described in terms of effective dimension five and six operators. A correction from the BMSSM operators allows us to consider new parameter space of Higgs sector which is not allowed in the MSSM. It can be regarded as a constrained version of general 2 Higgs doublet model (2HDM) as long as Higgs sector is concerned. We focus on the possibility that CP odd Higgs (A) mass is about 7 or 8 GeV and charged Higgs mass is comparable to W mass. At the same time one of the CP even Higgs (h) is light enough such that h and A production at the Z pole is kinematically allowed. The tension between forward backward asymmetry of bottom quark Ab_FB measured at LEP and the Standard Model prediction can be ameliorated if bottom quark pair produced from light CP even Higgs is taken into account.
Speaker: Dr DOYOUN Kim (Monash University)
• 17:30
. 30m
• 09:00 18:00
Room 216 - Top Quark Physics / Particle Astrophysics & Cosmology - TR4 & TR11 Room 216

### Room 216

#### Melbourne Convention and Exhibition Centre

Melbourne Australia
• 09:00
Charge asymmetry in top pairs at ATLAS 15m
In 7 TeV proton - proton collisions at the LHC, pairs of top and anti-top quarks are expected to be mostly produced through gluon fusion, in contrast to production at the Tevatron, where quark annihilation dominates. The ATLAS experiment has now recorded a large number of top quark pairs, allowing this domain to be explored in detail. We present measurements of top-quark charge asymmetry which constitute important tests of QCD and are sensitive to new physics. Measurements are presented in both, the single lepton and dilepton channel. Also, the lepton based charge asymmetry in top-quark pair events has been measured and will be presented.
Speaker: Dr Mario Giordani (INFN Trieste (IT))
• 09:15
Measurement of the charge asymmetry in top quark pair production in pp collisions (CMS) 15m
A measurement is presented of the charge asymmetry in top-pair production in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV. The data are collected by the CMS experiment during the year 2011. The analysis uses events with one charged lepton and at least four jets. In order to measure the charge asymmetry in charge-symmetric initial state processes, the difference of absolute pseudo-rapidities of top and anti-top is used. The asymmetry is measured inclusively and differentially, as functions of the invariant mass, the rapidity and the transverse momentum of the ttbar system. The results are compared with various theory predictions, and discussed in the context of forward-backard asymmetry measurements at Tevatron.
Speaker: Dr Thorsten Chwalek (KIT - Karlsruhe Institute of Technology (DE))
• 09:30
Asymmetry measurements in t-tbar at CDF 15m
The most intriguing property of top-quark physics observed so far is the forward-backward asymmetry in the production of top-quark pairs in proton anti-proton collisions at the Fermilab Tevatron. An unexpectedly sizable effect has observed in both the semi-leptonic and the all-leptonic decay channels of top-quark pairs, exceeding significantly the standard model predictions, and has motivated intensive theoretical investigations. Several models have already been proposed so far to explain the data, none of them fully successful. We present measurements of the asymmetry in both decay channels and studies of the asymmetry as a function of various kinematics variables, as well as related measurements of the top-quark pair production cross section differential in sensitive variables. We also present, for the first time, measurements of the asymmetry in bottom-quark pair production, which allows for exploring the asymmetry production mechanism in both the top and the bottom flavor sectors. All measurements are using the full CDF Run II sample.
Speaker: Dr Chris Hays (University of Oxford (UK))
• 09:45
Measurement of the forward-backward charge asymmetry in top quark pair production (D0) 15m
We present measurements of the forward-backward asymmetry and the lepton charge asymmetry in lepton plus jets and dilepton final states in top antitop quark pair production in proton antiproton collisions, using up to 10 fb-1 of data collected by D0 in Run II. We present unfolded results corrected for acceptance and resolution effects. In case of the lepton plus jets channel the analysis is also performed as function of the invariant mass of the ttbar pair. Furthermore, we give the combination of both channels and present first distributions sensitive to the top quark polarization.
Speaker: Dr Alexander Josef Grohsjean (DESY (DE) & Centre d'Etudes de Saclay (FR))
• 10:00
Top quark forward-backward asymmetry from gauged flavor symmetry 17m
The CDF and D0 experiments have reported measurements of the top quark forward-backward asymmetry A_{FB} which are (2.5-3.5) sigma away from the standard model predictions. In this talk it will be shown that this anomaly can be explained by new physics that arises when the flavor symmetry of the standard model is gauged in a maximal way. The flavor gauge symmetry would provide an understanding of the three family structure and the pattern of fermion masses. The Higgs doublets needed for generating the fermion masses contribute to A_{FB} in the right amount, while being consistent with all flavor changing constraints. The recent measurements of the top quark charge asymmetry A_C at the LHC by CMS and ATLAS provide additional constraints on these models. Interestingly, these constraints are compatible with models with extra Higgs doublets. Sharper predictions for A_C will be given, and the possibility of explaining an excess in the dijet invariant mass in the Wjj channel observed by CDF will be noted. New Higgs scalars in the mass range (150-400) GeV are predicted.
Speaker: Prof. Kaladi S. Babu (Oklahoma State University (US))
• 10:17
Refreshment Break 43m
• 11:00
Diagnosing top-quark Forward-Backward Asymmetry 15m
Recent measurements on the top-quark forward-backward asymmetry (A_FB) by the two (CDF & D0) Tevatron experiments show a more than 3 sigma deviation from the Standard Model prediction from the SM expectation of 5.2 ± 0.6%. Later about 3.1sigma enhancement was established on the basis of considering top-pairs only from the large tt_bar invariant mass region. In this talk, we will discuss about the diagnostic tests performed by us for the the aforementioned observation and provide some detail on the nature of the correct BSM model that causes such a large deviation.
Speaker: Dr Sudhir Kumar Gupta (Monash University (AU))
• 11:15
Searches in s-channel single top quark production at ATLAS 15m
We present searches for single top-quark production in the s-channel at 7 TeV proton-proton collisions with the ATLAS detector at the Large Hadron Collider. Limits. The result of a search for an exotic W’ boson production in the single top quark s-channel is also given.
Speaker: Dr Barbara Alvarez Gonzalez (Michigan State University (US))
• 11:30
FCNC in top quark production and decay at ATLAS 15m
Results on the search for flavor-changing neutral-currents (FCNC) in top-quark production and decay are reported, with data collected with the ATLAS detector at a center-of-mass energy of sqrt(s) = 7 TeV. The single top quark topology is used to place limits on sigma(qg -> t) x B(t -> Wb) (q=u,c). A search is also performed for top-quark pair events, with one top quark decaying through the t->Zq FCNC channel, and the other through the Standard Model dominant mode t->Wb. An upper limit on the t->Zq is set.
Speaker: Dr Markus Cristinziani (Universitaet Bonn (DE) & CERN)
• 11:45
Search for FCNC in top pair events in pp collisions (CMS) 15m
A search for flavor changing neutral currents in top quark decays is presented using a sample of top quark pair event candidates decaying via Wb and Zq into lνb and llq events. The search is performed at the CMS experiment at the LHC, using a data sample recorded in proton-proton collisions at a center-of-mass energy of 7 TeV. The observed number of events agrees with the standard model prediction, and no evidence of flavor changing neutral currents in top decays is found.
Speaker: Dr Yuan Chao (National Taiwan University (TW))
• 12:00
CP violation in top-quark physics 15m
The LHC will produce large numbers of top anti-top quark pairs providing an excellent opportunity to study in detail the properties of the top-quark. We discuss the use of T-odd correlations to extract information on the CP violating couplings of the top-quark at the LHC. We illustrate our discussion with two examples: CP violating anomalous top quark couplings; and CP violation in extended Higgs sectors, including color octets.
Speaker: Prof. German Valencia (Iowa State University (US))
• 12:15
Search for a Narrow ttbar Resonance in ppbar Collisions at sqrt(s) = 1.96 TeV (Combined D0, CDF) 17m
We report a search for a narrow ttbar resonance that decays into a lepton+jets final state based on an integrated luminosity of 5.3/fb of proton-antiproton collisions at sqrt(s)=1.96 TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider. We set upper limits on the production cross section of such a resonance multiplied by its branching fraction to ttbar which we compare to predictions for a leptophobic topcolor Z' boson. We exclude such a resonance at the 95% confidence level for masses below 835 GeV.
Speaker: Dr Azeddine Kasmi (Baylor University (US))
• 12:32
Lunch Break 1h 28m
• 14:00
Measurement of the top pair invariant mass distribution and search for New Physics (CMS) 15m
A measurement of the top-pair mass distribution in tt events is presented using proton-proton collision events at the LHC at a centre-of-mass energy of 7 TeV. The data are collected with the CMS experiment during the year 2011. The analysis is performed using several final states originating from top-pair production. The measurement is then used to search for massive resonances decaying into top-pairs. No significant deviations from the QCD expectations are observed, and upper limits on the new physics production cross-section as a function of the particle mass is determined
Speaker: Prof. Freya Blekman (Inter-University Institute for High Energies (BE))
• 14:15
Searches for ttbar resonances (ATLAS) 15m
Several extensions of the Stand ard Model predict the presence of new particles that couple to the top quark. With the dataset of proton - proton collisions collected by the ATLAS detector at the Large Hadron Collider we present searches for reson ances decaying to top - quark pairs.
Speaker: Dr Marcel Vos (Universidad de Valencia (ES))
• 14:30
Z' signals in polarised top-antitop final states 15m
We study the sensitivity of top-antitop samples produced at all energy stages of the Large Hadron Collider (LHC) to the nature of an underlying Z' boson, in presence of full tree level standard model (SM) background effects and relative interferences. We concentrate on differential mass spectra as well as both spatial and spin asymmetries thereby demonstrating that exploiting combinations of these observables will enable one to distinguish between sequential Z's and those pertaining to Left-Right symmetric models as well as E6 inspired ones, assuming realistic final state reconstruction efficiencies and error estimates. We go on to discuss other Z' models well suited to such searches in the top-anti top channel.
Speaker: Mr Ken Mimasu (University of Southampton (UK))
• 14:45
A charged Z' to explain the apparent disagreement in top-antitop asymmetires between Tevatron and LHC 15m
We propose a phenomenological model with a flavour changing electrically-neutral but not self-conjugated Z' to simultaneously explain the large Tevatron ttbar forward-backward asymmetry and the compatible with zero LHC charge asymmetry. We find that the model produces a natural cancellation in pp collisions which is suppressed in Tevatron's ppbar collisions, leading to a large forward-backward asymmetry. Being not self-conjugated, the model is not affected by same-sign top pair production. We find the region in parameter space compatible with the mentioned observables in addition to the measured cross-sections. We propose easy distinctive features of the model which can be tested in differential charge asymmetry measurements.
Speaker: Ms Estefania Coluccio Leskow (Buenos Aires University (AR))
• 15:00
Top Decays with Flavor Changing Neutral Higgs Interactions at the LHC 15m
We investigate the prospects for the discovery of a top quark decaying into one light Higgs boson along with a charm quark in top quark pair production at the CERN Large Hadron Collider (LHC). A general two Higgs doublet model is adopted to study the signature of flavor changing neutral Higgs interactions for $t \to c\phi^0$ or $\bar{t} \to \bar{c}\phi^0$ where $\phi^0$ is a CP-even scalar ($H^0$) or a CP-odd pseudoscalar ($A^0$). The dominant physics background is evaluated with realistic acceptance cuts as well as tagging and mistagging efficiencies. We have found abundant signal events and that our acceptance cuts reduce the physics background enough to establish a $5\sigma$ signal for $M_\phi \alt 130$ GeV at the early stage of LHC with $\sqrt{s} = 7$ TeV and an integrated luminosity of $10$ fb$^{-1}$. The discovery potential will be greatly enhanced with the full energy of $\sqrt{s} = 14$ TeV.
Speaker: Prof. Chung Kao (University of Oklahoma (US))
• 15:15
Search for anomalous Wtb couplings in ppbar collisions at sqrt(s) = 1.96 TeV (D0) 15m
We present new direct constraints on a general Wtb interaction using data corresponding to an integrated luminosity of 5.4 fb-1 collected by the D0 detector at the Tevatron ppbar collider. The standard model provides a purely left-handed vector coupling at the Wtb vertex, while the most general, lowest dimension Lagrangian allows right-handed vector and left- or right-handed tensor couplings as well. We obtain precise limits on these anomalous couplings by comparing the data to the expectations from different assumptions on the Wtb coupling using information from electroweak single top quark production. We combine this with results studying the helicity of W bosons from top quark decays in ttbar events.
Speaker: Prof. Kenneth Bloom (University of Nebraska-Lincoln (US))
• 15:30
Refreshment Break 30m
• 16:00
The Dark Energy Survey: status and science prospects 15m
The Dark Energy Survey Collaboration will soon begin a 5000 sq. deg. imaging survey of the southern galactic cap using a new 3 sq. deg., 520 Megapixel CCD camera, the Dark Energy Camera (DECam), with 5 filters (g,r,i,z and Y) mounted on the Blanco 4-meter telescope at the Cerro-Tololo Inter-American Observatory. Construction of DECam is complete, and installation and commissioning on the telescope are taking place in spring and summer 2012, with the expectation that the survey will begin in fall 2012. The survey data will be used to place new and tight constraints on the nature of dark energy via the history of the cosmic expansion rate and the growth of large-scale structure, using the four complementary techniques recommended by the Dark Energy Task Force: weak gravitational lensing, galaxy cluster counts, large-scale structure including baryon acoustic oscillations, and Type Ia supernovae. The science projections and prospects will be described, together with the status of the DECam installation and commissioning.
Speaker: Dr Marcelle Soares-Santos (Fermi National Accelerator Laboratory (US))
• 16:15
Cosmological neutrino mass constraint from the WiggleZ Dark Energy Survey 15m
The absolute neutrino mass scale is currently unknown, but can be constrained from cosmology. We use the large-scale structure information from the WiggleZ Dark Energy Survey to constrain the sum of neutrino masses. The WiggleZ high redshift star-forming blue galaxy sample is less sensitive to systematic effects from non-linear structure formation, pairwise galaxy velocities, redshift-space distortions, and galaxy bias than previous surveys. Through exhaustive tests using numerical dark-matter simulations of the WiggleZ survey, we demonstrate the at small scales common modelling approaches lead to systematic errors in the recovered cosmological parameters, and we use the simulations to calibrate a new non-linear fitting formula extending to small scales (k=0.3h/Mpc). We obtain an upper limit on the sum of neutrino masses of 0.60eV (95% confidence) for WiggleZ+Wilkinson Microwave Anisotropy Probe. Combining with priors on the Hubble Parameter and the baryon acoustic oscillation scale gives an upper limit of 0.29eV, which is the strongest neutrino mass constraint derived from spectroscopic galaxy redshift surveys.
Speaker: Dr Signe Riemer-Sorensen (University of Queensland)
• 16:30
Probing Flavor Transition Mechanisms with High Energy Astrophysical Neutrinos 15m
The determination of neutrino flavor transition mechanisms by neutrino telescopes is discussed. We parametrize these mechanisms in a basis which is very convenient for classifying flavor transition models.At very high energies (>10PeV), It is investigated that the electron neutrino fraction can be extracted without identifying muon and tau neutrinos by the neutrino telescope, such as ARA. We demonstrate how this observation, the electron neutrino fraction at very high energies, can probe the flavor transition mechanism.
Speaker: Prof. Kwang-Chang Lai (Chang Gung University (TW))
• 16:45
Latest Results on Searches for Dark Matter from IceCube 15m
Construction of the IceCube neutrino observatory was completed in early 2011, including a low-energy in-fill extension. This DeepCore sub-detector offers exciting opportunities for neutrino physics in the energy range of 10 GeV to 1 TeV. IceCube searches indirectly for dark matter via neutrinos from dark matter self-annihilations and has a high discovery potential through striking signatures. We report on the latest results from searches for dark matter self-annihilations in the Milky Way and nearby Galaxy clusters, as well as the search for signals from the Sun and Earth. Furthermore, a formalism for quickly and directly comparing event-level IceCube data with arbitrary annihilation spectra in detailed model scans, considering not only total event counts, but also event directions and energy estimators is presented. We show an application of this formalism to both model exclusion and parameter estimation in models of supersymmetry.
Speaker: Mr Matthias Danninger (Stockholm University (SE))
• 17:00
Dark matter searches with the ANTARES neutrino telescope: constraints to CMSSM and mUED models 15m
ANTARES is the largest neutrino telescope Northern hemisphere. It consists of a three-dimensional array of 885 photomultipliers to collect the Cherenkov light induced by relativistic muons produced in CC interactions of high energy neutrinos. One of the main scientific goals of the experiment is the search for dark matter. We present here the analysis of the recently unblinded data taken during 2007 and 2008 to look for a WIMP signal in the Sun. WIMPs are one of the most popular scenarios to explain the dark matter content of the Universe. They would accumulate in massive objects like the Sun or the Galactic Center and their self-annihilation would produce (directly or indirectly) high energy neutrinos detectable by neutrino telescopes. Contrary to other indirect searches (like with gamma rays or positrons), the search for neutrinos in the Sun is free from other astrophysical contributions, so the explanation of a potential signal in terms of dark matter is much more robust. The results are interpreted within two theoretical frameworks: CMSSM and mUED. Dark matter searches with neutrino telescopes has specific advantages with respect to other indirect searches. On the other hand, neutrino telescopes are particularly sensitive to spin-dependent cross-section, in contrast to direct search experiments. In particular, a potential signal from the Sun would can safely be interpreted as dark matter, contrary to excesses observed in cosmic rays or gamma rays, since there is no likely astrophysical alternative. We will present the results of the search for WIMPs in the Sun, using the recently unblinded data of 2007-2008. These results include limits in the muon and neutrino flux and also limits in the spin dependent cross section in the CMSSM and mUED frameworks. Moreover, an overview of the capabilities of other on-going analysis (Galactic Center, Sun with 2007-2011 data) will be also presented.
Speaker: Dr Juan de Dios Zornoza Gomez (IFIC (ES))
• 17:15
The status of KIMS experiment 15m
KIMS (Korea Invisible Mass Search) experiment has run its 100kg setup for last three years. We have given a new WIMP interaction rates for spin-independent and spin-dependent limits with 24524 kgdays data. We have further analyzed for the annual modulation amplitude with the last 3 years data. An analysis will be presented which has a limit comparable to DAMA's modulation amplitude. We have recently studied in detail and identified for the major internal and external background sources. Perspectives for KIMS experiment will be presented.
Speaker: Prof. Yeongduk Kim (Sejong University (KR))
• 17:30
Direct Search for Dark Matter with the LUX Experiment 15m
The Large Underground Xenon (LUX) experiment consists of a two-phase xenon time projection chamber, which is being deployed at a depth of 4850 feet in the Homestake mine in Lead, South Dakota. When LUX begins operation in Fall 2012 it will be the world’s most sensitive dark matter detector, with a fiducial target mass of 100 kg. Results from a surface lab commissioning and calibration run of LUX will be presented. Comparisons will be made to a detailed detector simulation, which is novel for such a class of detectors. Expected sensitivity and physics reach for detecting WIMP dark matter will be discussed, and compared to other contemporary direct search experiments. Plans for an order of magnitude larger detector will be outlined.
Speaker: Dr Karen Gibson (Case Western Reserve University (US))
• 17:45
Prospects of direct dark matter detection with DarkSide experiment 15m
DarkSide represents a staged program for direct detection of dark matter utilizing two-phase argon time projection chamber with the goal of achieving a high sensitivity limit or convincing detection of dark matter. The first stage in the program is DarkSide-10, a 10 kg prototype detector that was running in Laboratori Nazionali del Gran Sasso Counting Test Facility (CTF) during summer of 2011. The prototype was used to test argon light yield and other features necessary to achieve high sensitivity in the physics detector. The DarkSide-10 will be followed DarkSide-50 detector featuring a 50 kg active mass depleted argon target that is designed to reach sensitivity of 10^-45 cm^2 and will also be deployed in CTF. Besides the use of depleted argon that will allow use of pulse shape discrimination, other unique features such as neutron veto and muon veto along with active detector calibration will result in a detector capable of achieving background-free conditions. Construction of the neutron veto has been finished and DarkSide-50 is expected to start taking data in the Fall of 2012. The third stage of the program is DarkSide-G2, a second generation detector with 5 ton active mass of liquid argon reaching 10^-47 cm^2 sensitivity level, currently going into an R&D phase. In my talk, I will present DarkSide program, R&D activities and steps toward high sensitivity background-free measurement.
Speaker: Dr Jelena Maricic (Drexel University (US))
• 09:00 18:00
Room 217 - Heavy Ion Collisions / B-Physics / CP Violation - TR5/7/9 Room 217

### Room 217

#### Melbourne Convention and Exhibition Centre

Melbourne Australia
• 09:00
Measurement of boson production in lead-lead collisions at sqrt(s_NN)=2.76 TeV with the ATLAS detector 15m
Direct production of bosons are a powerful tool in heavy ion collisions. Their rates provide access to the initial state parton distribution functions, which are expected to be modified by nuclear effects.  They also provide a means to calibrate the expected energy of jets that are produced in the medium, and thus are a tool to probe the physics of jet quenching more precisely both through jet rates and fragmentation properties.  The ATLAS detector measures photons and Z->ee decays with its hermetic, longitudinally segmented calorimeter, which has excellent spatial and energy resolution, providing detailed information about the shower shape of each measured photon. ATLAS also measures the Z->mumu and W->munu in the same pseudorapidy range using the its muon system.  First results on the rates of isolated direct, Z and W from approximately 140 µb-1 of lead-lead data will be shown, as a function of transverse momentum, pseudorapidity and centrality, and their rates compared to expectations from perturbative QCD.
Speaker: Prof. Max Klein (University of Liverpool (UK))
• 09:15
Measurements of Jets and Jet Properties in sqrt(s_NN)=2.76 TeV PbPb Collisions with the ATLAS Detector at the LHC 15m
Jet quenching in the hot and dense medium created in ultra-relativistic heavy ion collisions is a well-established experimental phenomenon at RHIC. It has long been anticipated that the LHC heavy ion program would substantially advance the study of jet quenching by providing access to highly energetic jets and by measuring fully-reconstructed jets. Immediately following turn-on of the LHC in November, 2010, that expectation was fulfilled through the observation of large di-jet asymmetries that may indicate substantial jet quenching. In this talk we will present recent results from ATLAS aimed to provide further understanding of this phenomenon. Measurements of single jet production, di-jet correlations and jet fragmentation in Pb+Pb collisions at $\sqrt{s_{NN} = 2.76$~TeV will be presented. In addition to measurements from the 2010 data, results using the full 2011 run will also be presented, benefiting from a factor of 20 improvement in statistics.
Speaker: Prof. Erez Etzion (Tel Aviv University (IL) & CERN (CH))
• 09:30
J/Psi and Upsilon production in proton-nucleus collisions: lessons from RHIC for the 2012 proton-lead LHC run 15m
We will discuss the nuclear-matter effects on J/Psi and Upsilon production at RHIC and the LHC in proton-nucleus and, by extension, in nucleus-nucleus collisions. In the Upsilon case, we will argue that (i) the Upsilon break-up probability can be neglected in a first approximation, (ii) the gluon shadowing and antishadowing are not strong enough to describe forward RHIC data, (iii) the backward data hints at a gluon EMC effect, possibly stronger than the quark one, (iv) fractional energy loss provides a very convincing explanation for the Upsilon suppression seen by PHENIX in the forward region. Following these discussions, predictions for the LHC pPb run will be presented. In the J/Psi case, we will show that the fractional energy loss needed to explain the forward Upsilon suppression provides an alternative explanation to a strong gluon saturation for the strong forward J/Psi suppression at RHIC. We will discuss how this also affects J/Psi production in pA collisions at LHC energies. We will present results for J/Psi production in dAu at RHIC as function of rapidity, centrality and transverse momentum as well as for pA and AA collisions at the LHC. We will also pay special attention to two potential experimental issues in the interpretation of the LHC data, namely the absence of pp measurements at the same energy as for pPb and the difference in the transverse-momentum region accessed by the different detectors, i.e. ALICE vs. CMS and ATLAS.
Speakers: Jean-Philippe Lansberg (Ecole polytechnique), Dr Jean-Philippe Lansberg (Institut de Physique Nucléaire d'Orsay / IN2P3-CNRS (FR)), Jean-Philippe Lansberg (Ecole Polytechnique), Jean-Philippe Lansberg (IPN Orsay, Paris Sud U. / IN2P3-CNRS)
• 09:45
Suppression of high-pt heavy-flavour particles in Pb-Pb collisions at the LHC, measured with the ALICE detector 15m
The ALICE experiment studies nucleus-nucleus collisions at the LHC in order to investigate the properties of QCD matter at extreme energy densities. The measurement of open charm and open beauty production allows to probe the mechanisms of heavy-quark propagation, energy loss and hadronization in the hot and dense medium formed in high-energy nucleus-nucleus collisions. In particular, in-medium energy loss is predicted to be different for massless partons (light quarks and gluons) and heavy quarks at moderate momentum. The ALICE apparatus allows us to measure open heavy-flavour particles in several decay channels and with a wide phase-space coverage. We present the results on the nuclear modification factors for heavy flavour particle production in Pb-Pb collisions at sqrt(s_NN) = 2.76 TeV. Using proton-proton and lead-lead collision samples at sqrt(s) =2.76 and 7 TeV and at sqrt(s_NN) = 2.76 TeV, respectively, nuclear modification factors R_AA(pt) were measured for D mesons at central rapidity (via displaced decay vertex reconstruction), and for electrons and muons from heavy flavour decays, at central and forward rapidity, respectively. The large suppression observed in the high pt region, by a factor 2.5-4 in central Pb-Pb collisions with respect to the pp reference, indicates a strong in-medium energy loss of heavy quarks.
Speaker: Dr Andrea Dainese (INFN Padova (IT))
• 10:00
Quarkonia production in 2.76 TeV PbPb collisions in CMS 15m
The Compact Muon Solenoid (CMS) is fully equipped to measure hard probes in the di-muon decay channel in the high multiplicity environment of nucleus-nucleus collisions. Such probes are especially relevant for studying the quark-gluon plasma since they are produced at early times and propagate through the medium, mapping its evolution. CMS has measured the nuclear modification factors of non-prompt J/psi (from b-hadron decays), prompt J/psi, and Y(1S) in PbPb collisions at $\sqrt{s_{NN}} = 2.76$ TeV. Suppression of the excited Y-states is also studied in comparison to the Y(1S) state.
Speaker: Dr Nuno Viegas Guerreiro Leonardo (Purdue University (US))
• 10:15
Dijet imbalance in 2.76 TeV PbPb collisions in CMS 15m
Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV is studied with the CMS detector at the LHC. Jets are reconstructed using the energy deposited in the CMS calorimeters. A large dijet imbalance is observed in central PbPb collisions, which reduces in the more peripheral collisions. This observation is consistent with a jet quenching scenario, where the parton loose energy propagating through the hot and dense QCD medium. Detailed studies of the jet properties and jet-hadron correlations will be presented.
Speaker: Dr David Krofcheck (University of Auckland (NZ))
• 10:30
Refreshment Break 30m
• 11:00
Measurement of harmonic flow and particle correlations in lead-lead collisions at sqrt(s_NN)=2.76 TeV from ATLAS 15m
This talk will present the results of the azimuthal anisotropy of charged particle production and two particle correlations  in Pb + Pb collisions measured with the ATLAS experiment. The results are obtained with multi-particle correlations and compared with the event plane method. A complete set of v_n harmonics measured from central to peripheral events covers a pseudo-rapidity range of |eta| < 2.5 and a transverse momentum range 0.5 < p_T < 20 GeV. A comparison of the event plane and particle correlation methods allow to uniquely evaluate non-flow effects as well as the size of flow fluctuations. The v_1 flow and scaling of integrated elliptic flow, down to very low-p_T, will be discussed and compared to results of lower energy experiments.
Speaker: Prof. Ehud Duchovni (Weizmann Institute of Science (IL))
• 11:15
DIPSY - a new generator for minimum bias and heavy ion collisions 15m
We present a new Monte Carlo event generator based on the Mueller dipole model. The model is equivalent to leading logarithmic BFKL evolution and in our implementation we include several non-leading effects, such as energy-momentum conservation and a so-called swing mechanism to model saturation effects. In the end we can model all kinds of correlations and fluctuations between partons in the initial-state cascade and by adding final-state parton showers and string hadronization we can produce exclusive hadronic final states. So far the program has given promising results for minimum-bias events in proton collisions, but the main application may be for heavy ion collisions. Here we can again model kinds of correlations and fluctuations not only between partons in individual, but also between partons in different nucleons. This can then be used as the initial state of a hydrodynamical evolution model to better understand how observables are affected by initial-state effects. Alternatively it can be used as in proton collision with parton showers and hadronization to realistically model what heavy-ion collisions would look like in the absence of collective final-state effects.
Speaker: Prof. Leif Ingvar Lönnblad (Lund University (SE))
• 11:30
Particle production in Pb-Pb collisions with the ALICE experiment at LHC 15m
The ALICE experiment can benefit from its excellent particle identification capabilities to study hadron production in Pb-Pb collisions at \sqrt(s_NN) = 2.76 TeV, over a wide range of momenta. This allows one to probe different stages of the medium evolution. Transverse momentum spectra of identified particle and resonances characterize the bulk freeze-out properties and the dynamical evolution of the system. Results from hydrodynamics-motivated blast-wave model fits to the data are shown, while production yields and ratios are discussed from a thermodynamical point of view. Since the colliding nuclei have no net strangeness content, the study of strange and multi-strange particle production is an important probe of the early partonic stages of the collision. The enhancement of strangeness production in relativistic heavy-ion collisions relative to proton-induced reactions was one of the predicted signatures of the formation of the deconfined medium known as Quark-Gluon Plasma. ALICE results are presented. Moreover, high-pT particle production can be used to investigate the energy loss of the fast partons produced in early hard scatterings, while traversing the medium. To this purpose, measurements of the nuclear modification factor (R_AA) of identified particles have been performed and are discussed. Pb-Pb results are finally compared to measurements at lower energies and predictions for the LHC.
Speaker: Ms Francesca Bellini (Universita e INFN & University of Bologna (IT))
• 11:45
Collective flow and charged hadron correlations in 2.76 TeV PbPb collisions at CMS 15m
We report on the CMS measurements of charged hadron anisotropic azimuthal distributions from PbPb collisions at sqrt{s_{NN}} = 2.76 TeV. The results are presented as a function of transverse momentum, centrality and pseudorapidity and cover a broad kinematic range. Long range in pseudorapidity di-hadron azimuthal correlations are also studied and discussed in terms of the possible influence of the initial collision geomety. These results can provide constraints on the theoretical description of the early dynamics in the hot and dense medium created at the LHC and the transport properties through this medium.
Speaker: Dr Sandra Padula (UNESP - Universidade Estadual Paulista (BR))
• 12:00
Anisotropic Flow of Charged Particles at High Transverse Momentum in 2.76 TeV Pb-Pb Collisions at the LHC from ALICE experiment 15m
Anisotropic flow is sensitive to the properties of the deconfined state of matter produced during the course of a heavy-ion collision. We report on the inclusive photons anisotropic flow at forward rapidity, 2.3 < eta < 3.9, measured for Pb-Pb collisions at 2.76 TeV with ALICE at the LHC. Photons are reconstructed with ALICE Photon Multiplicity Detector (PMD), and the collision symmetry plane is estimated with charged particles produced at midrapidity |eta| < 0.8, which introduce large rapidity gap to reduce non-flow effects in the correlation analysis.
Speaker: Ms Anitha Nyatha (Indian Institute of Technology Bombay (IN))
• 12:15
Flow of strange and charm particles in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV measured with ALICE 15m
The ALICE experiment studies Pb-Pb collisions at the LHC in order to investigate the properties of the hot and dense QCD matter at extreme energy densities. Recent results from ALICE in identified particle flow allow for the exploration of the collective properties of the medium created in heavy-ion collisions. Due to their difference in mass, the strange and charm quarks are expected to couple differently to the system in the deconfined phase. In this talk, special attention is given to strange and charm particles which probe the medium differently and thus provide new constraints for the study of its properties. The talk will cover results on elliptic flow for K$^{+}$, K$^{0}_{s}$, $\Lambda$, $\Xi$, $\Omega$, $\Phi$, D$^{0}$ and D$^{*+}$ measured at midrapidity by ALICE in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV. The comparison with available models will also be shown.
Speaker: Mr Carlos Eugenio Perez Lara (NIKHEF (NL))
• 12:30
Scientific Program of NICA @ JINR 15m
Scientific program of NICA (Nuclotron-based Ion Collider fAcility) is now under realization phase at JINR (Dubna). The main goal of the program is an experimental study of hot and dense strongly interacting matter in heavy ion collisions at centre-of-mass energies of √sNN = 4-11 GeV (NN-equivalent) and at average luminosity of 10E27 cm-2 s-1 for Au (79+) in the collider mode (NICA collider). In parallel, fixed target experiments at the upgraded JINR superconducting synchrotron Nuclotron are carried out in the extracted beams of various nuclei species up to Au (79+) with maximum momenta of 13 GeV/c (for protons). The program also foresees a study of spin physics with extracted and colliding beams of polarized deuterons and protons at the energies up to √s = 26 GeV (for protons). The proposed program allows to search for possible signs of the mixed phase and critical endpoint, and to shed more light on the problem of nucleon spin structure. General design and construction status of the complex is presented.
Speaker: Prof. Vladimir Kekelidze (Joint Institute for Nuclear Research (RU))
• 12:45
Recent results and future plans form the NA61/SHINE experiment 15m
The NA61/SHINE (SPS Heavy Ion and Neutrino Experiment) is a fixed-target experiment to study hadron production in hadron-nucleus and nucleus-nucleus collisions at the CERN SPS. The experimental apparatus is a large acceptance Magnetic Spectrometer complemented with Time-Of-Flight detectors and a Projectile Spectator Detector. Its excellent capability for particle identification and momentum determination, even in complex events, makes the NA61/SHINE experiment well suited for pursuing a reach physics program which consists of three main topics: i) hadron-nucleus interactions: hadron production measurements for neutrino (T2K) and cosmic-ray (Pierre Auger Observatory) experiments ii) nucleus-nucleus interactions: hadron production measurements to search for the critical point of strongly interacting matter and to study the properties of the onset of the deconfinement iii) proton-proton and proton-nucleus interactions: measurement of inclusive and correlated yields of high pT hadrons to study their in-medium modifications i) Second generation long baseline neutrino oscillation experiments, like T2K, do require a very good knowledge of neutrino fluxes which means a more precise measurements of the production cross sections of pions and kaons. NA61/SHINE thanks to the large acceptance and particle identification in the forward region covers most of the phase space region of interest for T2K. So far pi+ and K+ differential cross section in p+C interaction at 31 GeV/c have been measured and published. Such measurements contributed significantly to the T2K measurement of electron neutrino appearance (nu_mu->nu_e) which led to the first indication of a non zero mixing angle theta_13 and to the measurement of muon neutrino disappearance (nu_mu->nu_mu). Preliminary results on K0_S production have been released as well. Precise knowledge of the neutral kaons cross section is in fact required for the accurate calculation of the nu_e and nu_e fluxes from K0_L->pi e nu_e decays. Measured charged pions and kaons data provide also important input to improve hadron production models prediction needed for the study of air shower initiated by ultra-high-energy cosmic particles. ii) and iii) NA61/SHINE aims to extend the NA49 ion program exploring a wider region of the phase diagram of strongly interacting matter within the range of thermodynamical variables (e.g. temperature and baryon chemical potential). Profiting from the successful increase in the data taking rate after the detector upgrade, NA61/SHINE is performing a scan the QCD phase diagram by varying both the energy (beam momentum 13A-158A GeV/c) and the size of the colliding nuclear system (p+p, p+Pb, Be+Be, Ar+Ca, Xe+La). The main goal is to find signatures of the critical point and to study the onset of the QGP formation by measuring the dynamical fluctuations, the azimuthal anisotropy and the identified hadron spectra and yields. Moreover, high statistics data will make possible the measurement of high pT hadron spectra. Successful data taking for p+p (13 to 158 GeV/c) and of Be+Be (40A, 75A and 150A GeV/c) interactions have been completed. From the analysis of p+p data at 20A, 31A, 40A, 80A and 158A GeV/c preliminary results are available on the energy dependence of the inclusive pion production, the transverse momentum fluctuations and the azimuthal angle fluctuations. All the achieved results and the analysis techniques will be described in detail with particular emphasis on the impact on the related physics measurements. Future data taking plans and the foreseen program of measurements will be presented as well.
Speaker: Dr Silvestro Di Luise (Eidgenoessische Tech. Hochschule Zürich (CH))
• 13:00
Electron-Ion Collisions at a Large Hadron electron Collider (LHeC Study Group) 15m
The Large Hadron electron Collider (LHeC) is a proposed facility which will exploit the LHC heavy ion beam for electron-nucleus scattering, using a new 60 GeV electron accelerator. This contribution, which is derived from the detailed simulations in the recently released Conceptual Design report, addresses the expected physics impact of the LHeC for heavy ion physics and nuclear parton density determinations. The kinematic coverage extends beyond previous deep inelastic lepton-ion experiments by nearly four orders of magnitude at low Bjorken x (from x ~ 10^-2 to x~ 10^-6) and is expected to be sufficient to reveal the non-linear dynamics which tame the low x growth of parton densities. The inclusive electron-lead cross section, as well as exclusive and diffractive channels, are explored as means of probing this new region of very high parton densities.
Speaker: Prof. Paul Newman (University of Birmingham (UK))
• 13:15
Lunch Break 30m
• 13:45
Prospects of measuring the CKM matrix element $V_{ts}$ at the LHC 15m
We study the prospects of measuring the CKM matrix element $\vert V_{ts}\vert$ at the LHC with the top quarks produced in the processes $p p \to t\bar{t}X$ and $p p \to t/\bar{t} X$, and the subsequent decays $t \to W^+s$ and $\bar{t} \to W^- \bar{s}$. To reduce the jet activity in top quark decays, we insist on tagging the $W^\pm$ leptonically, $W^\pm \to \ell^\pm \nu_\ell$ ($\ell =e, \mu, \tau$), and analyse the anticipated jet profiles in the signal process $t \to W s$ and the dominant background from the decay $t \to W b$. To that end, we analyse the $V0$ ($K^0$ and $\Lambda$) distributions in the $s$- and $b$-quark jets concentrating on the energy and transverse momentum distributions of these particles. The $V0$s emanating from the $t \to W b$ branch have displaced decay vertexes from the interaction point due to the weak decays $b \to c \to s$ and the $b$-quark jets are rich in charged leptons. Hence, the absence of secondary vertexes and of the energetic charged leptons in the jet provide additional ($b$-jet vs. $s$-jet) discrimination in top quark decays. These distributions are used to train a boosted decision tree (BDT), a technique used successfully in measuring the CKM matrix element $\vert V_{tb}\vert$ in single top production at the Tevatron. Using the BDT classifier, and a variant of it called BDTD, which makes use of decorrelated variables, we calculate the BDT(D)-response functions corresponding to the signal ($t \to W s$) and background ($t \to W b$). Detailed simulations undertaken by us with the Monte Carlo generator PYTHIA are used to estimate the background rejection versus signal efficiency for three representative LHC energies $\sqrt{s}=7$ TeV, 10 TeV and 14 TeV, of which only the analysis for the $\sqrt{s}=14$ TeV case is shown in detail. We argue that a benchmark with 10\% accuracy for the signal $t \to W s$) at a background ($t \to W b$ ) rejection by a factor $10^3$ (required due to the anticipated value of the ratio $\vert V_{ts}\vert^2/\vert V_{tb} \vert^2 \simeq 1.6 \times 10^{-3}$) can be achieved at the LHC@14 TeV with an integrated luminosity of 10 fb$^{-1}$.
Speaker: Prof. Fernando Barreiro (Universidad Autonoma De Madrid (ES))
• 14:00
b ->sgamma and b -> s l+ l- at BaBar 15m
The inclusive decay b-->s gamma, which in the standard model proceeds via the electroweak penguin process, is sensitive to contributions from physics beyond the standard model. Extensive theoretical literature discusses the contributions of new physics to the decay rate and CP asymmetry. While predictions for the exclusive decays such as B-->K* gamma suffer from large hadronic uncertainties associated with form factors of the final-state hadrons, the inclusive decays are theoretically better understood, with partonic rates calculated to a precision of a few percent. We present new results of the inclusive decay b-->s gamma using both a fully inclusive technique and the sum of 38 exclusive modes. In both techniques we take advantage of the clean e+e- environment. We report the branching fraction, CP asymmetry, and photon energy spectrum for these decays. In the standard model, the flavor-changing-neutral-current decays b-->d l+l- are suppressed by the electromagnetic coupling relative to the decay b-->d gamma and Cabibbo suppressed with respect to the decays b-->sl+l-. Being very rare and proceeding via an electroweak penguin or box diagram, these decays are sensitive probes of new physics, which may significantly increase the branching fraction. Using the full BABAR data set, we study the decays B+ -->pi+ l+l-, B0 -->pi0 l+l-, and B0 -->eta l+l-, where l=e or mu. We present updated branching-fraction upper limits for the individual pion modes and for the combined B-->pi l+l- decay. We also present the first upper limit on the branching fraction of the decay B0 -->eta l+l-. We study the rare decays B-->K(*)e+e- and B-->K(*)mu+mu- in a sample of 471 million BB events collected with the BABAR detector. We report measurements of the partial branching fractions, isospin asymmetry, K* polarization, and lepton forward-backward asymmetry in seven bins of dilepton mass squared. We also present the CP and lepton-flavor asymmetries for dilepton mass below and above the J/Psi resonance. Our results are compared with the standard-model predictions and those of other experiments. The inclusive, flavor-changing-neutral-current decay b-->sl+l- provides a probe of new physics and stringent tests of the standard model, as it is theoretically better understood than individual exclusive decays. We present new measurements of the inclusive decay B --> Xs l+ l-, where Xs is a hadronic system consisting of one charged or neutral K and 0-3 pions with at most one pi0, and l is an electron or muon. The measurement is based on the full BABAR Upsilon(4S) data set. We report the total branching fraction, partial branching fractions and CP asymmetries in five regions of dilepton mass using a sum-of-exclusive-modes technique.
Speaker: Prof. Gerald Eigen (University of Bergen (NO))
• 14:15
A global fit to extract the B->Xs gamma decay rate 15m
The measurements of the total B->Xs gamma decay rate and the determination of the CKM matrix element |Vub| play important roles in looking for new physics in the flavor sector of the Standard Model, complementary to the ongoing direct searches at the LHC. Their measurements from present and future B-factory data require the precise knowledge of the nonperturbative parts of the parton distribution function for the b quark in the B-meson (called the shape function). We present the state of the art theory and a global fit to BaBar and Belle data to extract the shape function and the B->Xs gamma decay rate using a model-independent framework with reliable theoretical uncertainties for the shape function, based on an expansion in a set of basis functions.
Speaker: Mr Florian Bernlochner (University of Victoria (CA))
• 14:30
Radiative B decays at LHCb 15m
Radiative B decays are sensitive probes of New Physics. We present the first results on these decays from the LHCb experiment, which are obtained with 1.0 fb-1 of proton-proton collision data collected in 2011. Results include the measurements of the branching fraction of B0s -> φ γ and the CP asymmetry in B0 -> K*0 γ.
Speaker: Dr Olivier Deschamps (Laboratoire De Physique Corpusculaire (FR))
• 14:45
Rare or forbidden B decays at Belle 15m
The quark transition $b \rightarrow s \nu\bar{\nu}$ is only possible within the Standard Model (SM) through higher order processes, which are highly suppressed compared to tree-level processes. The theoretical predictions of the decays where this quark process occurs are very precise because there is only one hadron in the final state and no charged lepton. However, in models beyond the Standard Model, these decays can be enhanced by orders of magnitude. The very small SM branching fractions and two undetectable neutrinos in the final state are the main challenges of this analysis. To be able to reconstruct these channels despite the missing neutrinos, the full reconstruction method is used. We present the results of the search for $B \rightarrow h^{(*)}\nu\bar{\nu}$ decays based on the full data set collected at the $\Upsilon(4S)$ resonance with the Belle detector operating at the KEKB asymmetric-energy $e^+e^-$ collider. We report on a search for heavy neutral leptons in $B$-meson decays. The results are obtained using a data sample that contains $772 \times 10^6\,B\bar{B}$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. No signal is observed and upper limits are set on mixing of heavy neutral leptons with left-handed neutrino of the SM in the mass range $0.5-5.0\,\textrm{GeV}/c^2$. We report a search for $B$ decays into invisible final states using a data sample of 656.7 million $B\overline{B}$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}e^{-}$ collider. The signals of invisible final states are identified by fully reconstructing the accompanying $B$ meson and requiring no other charged particles and no extra energy deposited in the calorimeter. The measured upper limits are reported and the corresponding physics are discussed. The HyperCP experiment at Fermilab reported the observation of three events for $\Sigma^+ \to p \mu^+ \mu^-$ decay. The dimuon masses of the observed events are clustered around $214.3 {\rm MeV}/c^2$ within the detector resolution of $1 {\rm MeV}/c^2$. These decays might be interpreted as a two-body decay, $\Sigma^+ \to p X^0(214)$, with $X^0 (214) \to \mu^+ \mu^-$. Several hypotheses are suggested to interpret $X^0 (214)$ including a sgoldstino in SUSY, a light Higgs boson in NMSSM, and a $U$ boson. We report on a search for $X^0$ in $B^0 \to K^+ (\pi^+) \pi^- X^0$ decays using 772 million $B$ meson pairs collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. We extend the search to a larger mass region between $212 {\rm MeV}/c^2$ and $1.8 {\rm GeV}/c^2$ with different values of the $X^0$ lifetime. We study the charmless $B^0$ decays with final state particles $p \bar{\Lambda} \pi^- \gamma$ using the full data sample collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. This decay is believed to proceed via the $b \to s \gamma$ electro-weak penguin process at the quark level. We also search for the intermediate three-body decays using the same final state particles. Observed branching fractions or upper limits are reported. We present a study of B decays to $K^{(*)}$ and two leptons ($e,\ \mu$) in the full Belle $\Upsilon (4S)$ data set containing $771 \times 10^6~B\bar{B}$ pairs. The flavor-changing neutral-current process responsible for this decay, $b \rightarrow s \ell^{+} \ell^{-}$, proceeds via electro-weak penguin diagrams in the Standard Model. However, this process is sensitive to new physics due to contributions from Beyond the Standard Model particles in these diagrams. We report the differential branching fraction, isospin asymmetry, $K^{*}$ polarization, and forward-backward asymmetry ($A_{FB}$) as a function of $q^2 = M_{\ell\ell}^{2} c^2$. The flavor-changing-neutral-current decays such as $B \to X_s \gamma$ are sensitive to new physics beyond the Standard Model as particles of new physics may enter the loop and affect the decay process. While the branching fraction of the inclusive $B \to X_s \gamma$ decays has been measured by several experiments with good precision, other quantities such as the $CP$ and isospin asymmetries of the inclusive $B \to X_s \gamma$ are less well determined. To facilitate the precise measurements of such quantities, we study inclusive $B \to X_s \gamma$ decays using a hadronic tagging method, where one of the $B$ mesons in a $B\bar{B}$ event is fully reconstructed in the hadronic final state. In this paper, we show preliminary results of this study using the full Belle data sample of $711~{\rm fb}^{-1}$ integrated luminosity recorded by the Belle detector at the $\Upsilon(4S)$ resonance at the KEKB asymmetric-energy $e^+ e^-$ collider.
Speaker: Ms Oksana Brovchenko (KIT - Karlsruhe Institute of Technology (DE))
• 15:00
Studies of rare beauty and charm decays with the CMS experiment 15m
The rare decays B_s(B^0)->mu+mu-, B0->K*mu+mu- and D0->mu+mu- are excellent tests of the flavor sector of the Standard Model and are sensitive to new physics. We report on studies of these decays performed with the CMS experiment using pp collisions data collected in 2011 at a centre-of-mass energy of 7 TeV. We present the first observation of the excited B baryon Xi_b* in the strong decays to Xi_b- and a charged pion, performed with the CMS experiment at sqrt(s)=7 TeV. In addition, we present measurements of B hadron lifetimes.
Speaker: Mr Keith Ulmer (University of Colorado at Boulder (US))
• 15:15
Studies of the electroweak penguin transitions b -> s μ+ μ– and b -> d μ+ μ– at LHCb 15m
Rare b -> s μ+ μ– transitions that proceed via flavour changing neutral currents are suppressed in the SM and provide a sensitive probe of new physics contributions entering in competing diagrams. The dataset collected with the LHCb experiment has enabled measurements to be made in decays such as B0 -> K*0 μ+ μ–, B+ -> K+ μ+ μ– and B0s -> φ μ+ μ–. Particularly interesting are the angular and isospin asymmetries in the decay B0 -> K(*)0 μ+ μ–, which are sensitive probes of new physics. The large statistics of reconstructed B mesons allow, for the first time, experimental access to b -> d μ+ μ– transitions, such as B+ -> π+ μ+ μ–, which are further suppressed in the SM. The latest results on these decay modes will be presented.
Speaker: Dr Abraham Antonio Gallas Torreira (Universidade de Santiago de Compostela (ES))
• 15:45
Refreshment Break 15m
• 16:00
Flavour data constraints on supersymmetry and SuperIso 15m
I will review flavour physics constraints on supersymmetric models and in particular those from b to s gamma, Bs to mu+ mu- and B to K* mu+mu- (with an emphasis on the new LHCb results). These rare transitions provide valuable information in the quest for new physics and are complementary to the direct searches. The SuperIso program will also be described.
Speaker: Dr Nazila Mahmoudi (CERN (CH) & Clermont Ferrand University (FR))
• 16:15
Rare kaon decay measurements with NA62/NA48 minimum bias data 15m
The NA62 (phase-I) experiment at CERN collected a large sample of charged kaon decays in 2007-2008, allowing one to study these decays with a high precision. The first result of the helicity-suppressed ratio RK of the K+- --> e+- nu and K+- --> mu+- nu decay measurement based on this sample is presented. The result is in agreement with the Standard Model expectation, and constrains two-Higgs-doublets extension of the Standard Model. The status of analyses of rare decay K+- --> e nu gamma and very rare decay K+ -> pi+ pi0 e+ e- collected with a low intensity beam and minimum bias trigger conditions in 2007, is presented as well. Using the minimum bias data of NA62 and the data of NA48/2 experiment collected with minimum bias trigger in 2004, a large sample of K+- --> pi gamma gamma decays has been selected and analyzed. This analysis led to a precision test of the Chiral Perturbation Theory. The NA62 experiment at CERN SPS (phase-II) aims to collect of the order of 100 K+->p+nn events in two years of data taking, keeping the background at the level of 10%. The physics prospects and the status of the construction of the experiment will be presented.
Speaker: Prof. Vladimir Kekelidze (Joint Inst. for Nuclear Research (RU))
• 16:30
ORKA, The Golden Kaon Experiment: Precision measurement of $K^+\to\pi^+\nu \bar\nu$ and other ultra-rare processes 15m
Precision measurement of the ultra-rare $K^+\to\pi^+\nu \bar\nu$ decay at Fermilab would be one of the most incisive probes of quark flavor physics this decade. Its dramatic reach for uncovering new physics is due to several important factors: The branching ratio is sensitive to most new physics models which extend the Standard Model to solve its considerable problems. The Standard Model prediction for BR($K^+\to\pi^+\nu \bar\nu$) is broadly recognized to be theoretically robust at the 5--10\% level. Only a precious few accessible loop-dominated quark processes can be predicted with this level of certainty. The $K^+\to\pi^+\nu \bar\nu$ branching ratio is highly suppressed in the Standard Model to the level of $< 10^{-10}$ ($<1$ part in 10 billion). This suppression allows physics beyond the Standard Model to boost the branching fraction with enhancements of up to a factor of five above the Standard Model level. The certainty with which the Standard Model contribution to $K^+\to\pi^+\nu \bar\nu$ can be predicted will permit a 5$\sigmA$ discovery potential for new physics even for enhancements of the branching ratio as small as 35\%. This sensitivity is unique in quark flavor physics and allows probing of essentially all models of new physics that couple to quarks within the reach of the LHC. Furthermore, a high precision measurement of $K^+\to\pi^+\nu \bar\nu$ is sensitive to many models of new physics with mass scales well beyond the direct reach of the LHC. The ORKA initiative aims to precisely measure the $K^+\to\pi^+\nu \bar\nu$ process based on established detector techniques driven with the Fermilab Main Injector high intensity proton source. In recognition of this exciting opportunity the Fermilab director has recently granted scientific approval to the ORKA proposal. The physics reach and experimental techniques of the ORKA initiative will be discussed, as well as opportunities for collaboration in the ORKA adventure and the longer term Intensity Frontier roadmap at Fermilab.
Speaker: Prof. Mike Hildreth (University of Notre Dame (US))
• 16:45
Rare and forbidden B decays at BaBar 15m
Lepton-flavor violation in the standard model occurs only via neutrino mixing, and is thus suppressed by powers of (m_nu / m_W)^2 to far below observable levels. However, in many extensions of the standard model, lepton-flavor violation involving third-generation fermions may be highly enhanced. Study of B decays involving a tau lepton in the final state is complicated by the presence of final-state neutrinos. At an e+e- B factory, this difficulty is handled by reconstructing both B mesons in the event, taking advantage of the high luminosity and clean event environment. Using this technique, we set the first upper limits on the branching fractions of B-->K tau e, B-->pi tau e, and B-->pi tau mu, and improve our previous limit on B-->K tau mu, at the level of a few times 10^-5. The decay of a B0 meson into two neutrinos is suppressed by a helicity factor of order (m_nu / m_B)^2 in the standard model. The same decay with an additional photon in the final state is also predicted to be unobservably rare, with a branching fraction at the level of 10^-9. Thus, observation of such decays would constitute evidence for new physics, and several scenarios beyond the standard model predict branching fractions as high as 10^-6. The search for invisible (+ photon) decays of the B0 requires fully reconstructing the entire event and tagging the presence of the B0, and so can be performed only at an e+e- B factory. We present the results of a new analysis based on the full BABAR dataset and improved reconstruction, obtaining limits several times tighter than the previous results, at the level of 10^-5. The decays B-->K(*)nu nubar are flavor-changing neutral-current (FCNC) processes that proceed via a box or penguin diagram. FCNC decays are suppressed in the standard model, with branching-fraction predictions in the 10^-6 range, but they may be enhanced by new-physics contributions. Due to the final-state neutrinos and the small decay rate, study of these decays can currently be performed only at an e+e- B factory, where reconstruction of the other B in the event (the “tag B”) is possible. We report the results of a new search for these decays using hadronic decays to identify the tag B in the full BABAR data set. We also use our data to search for invisible decays of the J/psi. Lepton number is conserved in the standard model, but may occur in scenarios beyond the standard model, for example, due to the existence of Majorana neutrinos. We report the results of a new search for lepton-number violation in the decays B+ -->K-e+e+, B+ -->pi-e+e+, B+ -->K-mu+mu+, B+ -->pi-mu+mu+, and set upper limits on the branching fractions at a few times 10^-8. Study of the di-electron modes has been performed only in e+e- B factories, and in these modes we improve on previous limits by two orders of magnitude.
Speaker: Dr Steven Robertson (McGill University (CA))
• 17:00
Search for Bs(B0)--> mu mu and other exclusive B decays 15m
The search for the rare decay Bs to mu+ mu- with the ATLAS detector is discussed. Results form analysis of 2.4fb-1 of data collected in 2011 are presented. The production of B-mesons has been studied by ATLAS in several exclusive channels containing a ]/psi. Several analysis are discussed, including the recent observation of Bc -> ]/psi pi.
Speaker: Dr Paolo Iengo (INFN (IT))
• 17:15
Searches for very rare decays to purely leptonic final states at LHCb 15m
We present a review of the searches for very rare decays to muon final states performed at LHCb using 1.0 fb–1 of pp collisions at 7 TeV centre of mass energy. Flavour changing neutral current processes, such as B0s -> μ+ μ– are highly suppressed in the Standard Model (SM). Such decays therefore allow the contributions from new processes or new heavy particles to significantly modify the expected SM rates. Charged lepton flavour violating processes (LFV), such as the neutrinoless τ+ -> μ+ μ– μ+ decay, have vanishingly small decay rates in the SM, but can be significantly enhanced in extended models. We report the latest results on these channels from the LHCb dataset.
Speaker: Mr Mathieu Perrin-Terrin (Centre de Physique des Particules de Marseille, Université d'Aix-Marseille (FR))
• 17:30
B physics at SuperB 15m
SuperB will collect 75ab^-1 of data at the Y(4S). Using this data, the experiment will be able to study rare B decays such as B to l nu and K(*)nu nubar as well as perform precision measurements of the angles of the unitarity triangle and improving measurements of |Vub| and |Vcb|. A few ab^-1 run at the Y(5S) will allow this experiment to search for rare decays of the B_s meson as well as measuring a_SL.
Speaker: Claudia Cecchi (Universita e INFN (IT))
• 17:45
Physics with the Belle II experiment 15m
The B factories — the Belle detector at the KEKB collider in KEK and the BaBar detector at the PEP II in SLAC — have, in more than a decade of data taking, outreached the initial expectations on the physics results. They pointed out few hints of discrepancies between the Standard Model (SM) predictions and the results of the measurements. To experimentally verify the current hints of possible new particles and processes often addressed as the New Physics(NP) a new generation of B factories - the Super B factories - are planned to start operation around 2015. The so-called precision frontier represented by the machines requires the achieved luminosities of the B factories to be raised by O(10^2). We will present the planned measurements and some of the expected precisions on various physics observables which will be reached by the Belle II detector currently being built at KEK. We will comment on the tests of various NP models that will be possible with the upgraded detector.
Speaker: Prof. Mikhail Danilov (ITEP Institute for Theoretical and Experimental Physics (RU))
• 09:00 18:05
Room 218 - Detectors and Computing for HEP - TR13 Room 218

### Room 218

#### Melbourne Convention and Exhibition Centre

Melbourne Australia
• 09:00
ATLAS Silicon Microstrip Tracker and Pixel Detector: Status and Performance 15m
The Semi-Conductor Tracker (SCT) and the Pixel Detector are the key precision tracking devices in the Inner Detector of the ATLAS experiment at CERN LHC. The SCT is a silicon strip detector and is constructed of 4088 silicon detector modules for a total of 6.3 million strips. Each module is designed, constructed and tested to operate as a stand-alone unit, mechanically, electrically, optically and thermally. The SCT silicon micro-strip sensors are processed in the planar p-in-n technology. The signals from the strips are processed in the front-end ASICS ABCD3TA, working in the binary readout mode. The Pixel Detector consists of approximately 80 million pixels that are individually read out via chips bump-bonded to 1744 n-in-n silicon substrates. In the talk the current status of the SCT and Pixel Detector will be reviewed. We will report on the operation of the detectors including an overview of the issues we encountered and the observation of significant increases in leakage currents (as expected) from bulk damage due to non-ionising radiation. The main emphasis will be given to monitoring, calibration procedures, timing optimization, detector performance. and the data quality during the many months of data taking (the LHC delivered 47pb-1 in 2010 and 5.6fb-1 in 2011 of proton-proton collision data at 7 TeV, and two times one-month periods of heavy ion collisions). The SCT and Pixel Detector have been fully operational throughout all data taking periods. The running experience will then be used to extract valuable lessons for future silicon strip detector and pixel detector projects.
Speaker: Dr Kendall Reeves (University of Texas at Dallas (US))
• 09:15
Operation and Performance of the CMS Silicon Tracker 15m
The CMS silicon tracker is the largest silicon detector ever built. It consists of a hybrid pixel detector with 66 million channels and a 200 m2 silicon strip detector with 10 million read out channels. The presentation describes the operation of this detector during the first three year of LHC both during proton-proton as well as heavy ion collisions. Results on the operational performance are presented including alignment, calibration, S/N, timing, etc. Reconstructed photon conversions and nuclear interactions are used to evaluate the material in the tracker. The resolution and efficiency of the track and vertex reconstruction are measured with data and compared to the results from simulation. With increasing integrated luminosity, monitoring of radiation-induced effects becomes more and more important. Our methods for measuring the evolution of full depletion voltage and leakage current will be presented and the results discussed.
Speaker: Dr Erik Butz (Massachusetts Inst. of Technology (US))
• 09:30
Status of the Atlas Calorimeters: their performances after two years of LHC operation and plans for future upgrades. 15m
The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider (LHC) at CERN. Its calorimeter system measures the energy and direction of final state particles with pseudo rapidity $|\eta| < 4.9$. Accurate identification and measurement of the characteristics of electromagnetic objects (electrons/photons) are performed by liquid argon (LAr)-lead sampling calorimeters in the region $|\eta| < 3.2$, using an innovative accordion geometry that provides a fast, uniform azimuthal response without gaps. The hadronic calorimeters measure the properties of hadrons, jets, and tau leptons, and also contribute to the measurement of the missing transverse energy and identification of muons. This is done in the region $|\eta| < 1.7$ with a scintillator-steel sampling calorimeter, and in the region $1.4 < |\eta| < 3.2$ with a copper-LAr sampling calorimeter. The coverage is extended to $|\eta| < 4.9$ by an integrated forward calorimeter (FCal) based on LAr with copper and tungsten absorbers. Following installation in 2004-2006, the calorimeters were extensively commissioned prior to first collisions in 2009. Since then, over 5 fb$^{-1}$ of data have been collected. Results on the calorimeters' operation and performance will be presented, including the calibration, stability, absolute energy scale, uniformity, and time resolution. These results demonstrate that the calorimeters are performing well within the design requirements and are giving reliable input to the physics analyses. Although LHC data-taking is expected to continue for a number of years, plans are already under way for operation at an instantaneous luminosity about 5 times the original design of $10^{34}$ cm$^{-2}$ s$^{-1}$, referred to as the HL-LHC. The calorimeter upgrade involves two phases. In the first, upgrades to the LAr calorimeter electronics will provide more granular information to the trigger and hence reduce the effects of the high pile-up noise. The second phase will be devoted to the complete replacement of the readout electronics of both the scintillator and LAr calorimeters. An additional complication may also arise in the case of the liquid argon hadronic calorimeter, where a replacement of the cold preamplifiers may be needed to cope with the radiation levels. Finally, for the FCal, the increased ionization load at the HL-LHC poses a number of problems that may degrade its performance. These include beam heating, space charge effects in the LAr-gaps, and HV losses due to increased current draws through the current-limiting resistors. A number of proposed solutions will be discussed.
Speaker: Dr Carlos Solans Sanchez (Universidad de Valencia (ES))
• 09:45
Performance of the CMS electromagnetic calorimeter at the LHC and role in the hunt for the Higgs boson 15m
The Electromagnetic Calorimeter (ECAL) of the Compact Muon Solenoid (CMS) experiment at the LHC is a hermetic, fine grained, homogeneous calorimeter, comprising 75,848 lead tungstate (PbWO4) scintillating crystals, located inside the CMS superconducting solenoidal magnet. The scintillation light is detected by avalanche photodiodes (APDs) in the barrel section and by vacuum phototriodes (VPTs) in the two endcap sections. A silicon/lead pre-shower detector is installed in front of the endcaps in order to improve γ/pi0 discrimination. Precise calibration of the ECAL detector is required. This includes inter-calibration, to account for the differing response of channels, and calibration of the energy scale. The performance obtained during the first LHC physics runs in 2010 and 2011 is presented and the role of the ECAL in the hunt for the Higgs boson, through the 2-gamma decay mode, is discussed.
Speaker: Dr Riccardo Paramatti (INFN - Rome I (IT))
• 10:00
Luminosity determination in p-p collisions at center-of-mass energy of 7 TeV using the ATLAS detector at the LHC 15m
A precision luminosity measurement is of critical importance for the ATLAS physics program, both for searches for new physics as well as for precision measurements of Standard Model cross-sections.  The absolute calibration of the ATLAS luminosity scale is based on beam separation (van der Meer) scans which are used to calibrate a variety of luminosity-sensitive detectors.  These detectors then measure the luminosity continuously during regular physics operations.  Uncertainties on the luminosity measurement are evaluated based on the calibration procedure itself, plus uncertainties related to extrapolating this calibration to the entire physics data sample.  The final luminosity measurement for the ATLAS detector during p-p collisions at center-of-mass energy of 7 TeV in 2010 and 2011 is presented, along with prospects for luminosity measurements in p-p collisions at 8 TeV in 2012.
Speaker: Mr Eric Torrence (University of Oregon (US))
• 10:15
Measurements of the luminosity and normalised beam-induced background using the CMS Fast Beam Condition Monitor 15m
The CMS Beam Conditions and Radiation Monitoring system (BRM) is installed to protect the CMS detector from high beam losses and to provide feedback to the LHC and CMS on the beam conditions. The Fast Beam Condition Monitor (BCM1F), one of the sub-detectors in the BRM system, is installed inside the pixel volume close to the beam pipe and consists of two planes of 4 modules each located 1.8 m away from the IP, on both ends. It uses single-crystal CVD diamond sensors, radiation hard front-end electronics and an optical transmission of the signal. It is designed for single particle rate measurements, detecting both machine induced beam background and collision products on a bunch-by-bunch basis. Presented is the implementation of the normalized online beam-induced background measurement and the online instantaneous luminosity measurement. The method for determining the luminosity from the measured rates, including the absolute calibration using the Van der Meer scan, and the measurement performance will be described.
Speaker: Mr Nathaniel Jay Odell (Northwestern University (US))
• 10:30
Diamond sensors in HEP 15m
Progress in experimental particle physics in the coming decade depends crucially upon the ability to carry out experiments at high energies and high luminosities. These conditions imply that future experiments will take place in very high radiation areas. In order to perform these complex and expensive experiments new radiation hard technologies will have to be developed. Chemical Vapour Deposition (CVD) diamond is being developed as a radiation tolerant material for use very close to the interaction region where detectors may have to operate in extreme radiation conditions. During the past few years many CVD diamond devices have been manufactured and tested. As a detector for high radiation environments CVD diamond benefits substantially from its radiation hardness, very low leakage current, low dielectric constant, fast signal collection and ability to operate at room temperature. As a result CVD diamond now has been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of colliders. CVD diamond is being considered as a sensor material for the particle tracking detectors closest to the interaction region where the most extreme radiation conditions exist. We will present the state-of-the-art of the radiation tolerance of the highest quality CVD diamond material for a range of proton energies, pions and neutrons obtained from strip detectors constructed with this material. Recently single crystal CVD diamond material has been developed which resolves many of the issues associated with polycrystalline material. We will also present recent results on radiation tolerance obtained from strip detectors constructed from this new diamond material. We will discuss the use of diamond detectors and their survivability in the highest radiation environments. Currently diamond is deployed in HEP experiments for two tasks: for beam conditions monitoring and measurement of luminosity. Beam conditions can be deduced either from beam induced current measurements replacing the commonly used ionization chambers by CVD diamond pad detectors (e.g. ATLAS BLM; CMS BCM1, BCM2) or by particle counting (ATLAS BCM; CMS BCMF). Due to its fast response and insensitivity to pile-up, ATLAS BCM also serves as the preferred luminosity monitor. As a result of positive experience with the ATLAS BCM an upgraded Diamond Beam Monitor (DBM) is being prepared for installation during the 2013-14 LHC shutdown. This detector will consist of 8 three-layer telescopes of pixelated diamond detectors. Each plane will have ~27k active pixels. The telescopes will provide sub-mm impact parameter resolution adding spatial information on the origin of backgrounds to the already precise (sub-ns) timing information from the BCM. This talk will describe the design and construction of both the ATLAS BCM and DBM systems as well as showing results from the first two years of BCM operation and test-beam studies of the DBM modules.
Speaker: Prof. Marko Mikuz (University of Ljubljana, Jozef Stefan Institute (SI))
• 10:45
Refreshment Break 15m
• 11:00
Operations and Performance of the CMS DT and RPC muon systems 15m
The Drift Tubes (DT) detector in the CMS experiment triggered and recorded high quality data during the LHC run in 2011, observing muons from pp collisions at a center of mass energy of 7 TeV. More than 99% of the detector channels participated in data taking with very good performances in terms of up-time and efficiency. Prompt data were monitored in order to evaluate noise and backgrounds and to determine calibrations. The DT system showed excellent performance: at the trigger level, with excellent bunch crossing identification capability, despite long drift times intrinsic to the detector technology; and at the reconstruction level, reaching very good spatial and temporal resolution. Weak points of the current detector and electronics were also identified, and actions to mitigate their possible impact were taken during the run where possible. Future developments were planned in view of upgrade campaigns during the accelerator shutdowns. The first results of the 2012 run at 8 TeV center of mass energy will also be presented. The Resistive Plate Chambers are used in CMS as dedicated muon trigger in both barrel and endcap region. They also contribute to the identification of the muons together with Drift tube in the barrel and Cathod Strip Chambers in the endcaps. We will report the operations and performance of the system after two years of LHC activities with increasing instantaneous luminosity. Special attention will be given to the stability of the system and to the working point calibration procedures.
Speaker: Dr Gabriella Pugliese (Universita e INFN & Politecnico di Bari (IT))
• 11:15
Study of the performance of the muon and tau identification at ATLAS 15m
Charged leptons play an important role in the physics programme at the LHC. The performance of identification of charged leptons must be know with high precision. This talk present the studies of the muon and tau identification performance at the ATLAS experiment. In 2012 the LHC is operated in a mode leading to up to 40 inelastic pp collisions per bunch crossing, so-called ”pile-up”, with an average number of 20 inelastic collisions. The high multiplicity of charged tracks in the inner tracking detector makes it difficult to reconstruct and identify muons at high eﬃciency and low misidentiﬁcation rate. Di-muon decays of J/ψ mesons and Z bosons have been used to study the muon reconstruction and identiﬁcation eﬃciency as a function of the muon transverse momentum from pT = 4 GeV to pT = 100 GeV and the number of inelastic collisions per event. The misidentification rate was determined with Z+jet events. Optimal identification of hadronically decaying tau leptons is achieved by using detailed information from tracking and calorimeter detector components. Variables describing the properties of calorimeter energy deposits and track reconstruction within tau candidates are combined in multi-variate discriminants, to achieve high rejection against backgrounds, which is challenging in high luminosity environments. The identification efficiencies are measured by W->taunu and Z->tautau events. The energy scale uncertainties for tau leptons are determined by investigating single hadron calorimeter response, as well as kinematic distributions in Z->tautau events.
Speaker: Dr Mansoora Shamim (University of Oregon (US))
• 11:30
Alignment procedures for the CMS Silicon Tracker detector 15m
The CMS all-silicon tracker consists of 16588 modules: aligning them with the desired precision of a few micrometers is only feasible using track based alignment procedures. Ultimate precision is now achieved by the determination of sensor curvatures in addition to the local translation and rotation of modules in space. This challenges the alignment algorithms to determine about 200k parameters simultaneously. This is achieved using the Millepede II program, interfaced with CMS software. The alignment of the detector is also monitored using its built in Laser Alignment System. For this, 3% of the silicon strip modules are illuminated by the laser beams, assuring a continuous surveillance during data taking. The system allows to monitor the alignment changes with a precision better than 10 micron and to measure the absolute alignment parameters better than 100 microns. The main remaining challenge for the alignment are global distortions that systematically bias the track parameters and thus physics measurements. These distortions are controlled by adding further information into the alignment workflow, e.g. the mass of decaying resonances. The orientation of the tracker with respect to the magnetic field of CMS is determined with a stand-alone chi-square minimization procedure. The resulting geometry is finally carefully validated: the monitored quantities include the basic track quantities for tracks from both collisions and cosmic muons and physics observables like resonance masses.
Speaker: Dr Roberto Castello (Universite Catholique de Louvain (BE))
• 11:45
Tracking, vertexing and b-tagging performance in ATLAS 15m
ATLAS is a multipurpose experiment at the LHC proton-proton collider. In order to reconstruct trajectories of charged particles, ATLAS is equipped with a tracking system built using different technologies, silicon planar sensors (pixel and micro-strip) and gaseous drifttubes, all embedded in a 2T solenoidal magnetic field. ATLAS physics goals require high resolution, unbiased measurement of all charged particle kinematic parameters in order to assure e.g. accurate interaction and decay vertex finding. The precision on track parameters critically depend on the systematic effects related to the alignment of the tracking system. In particular, small collective deformations due to sudden environmental changes (temperature, magnetic field) have to be identified and corrected in quasi-real time. The reconstruction of the primary interaction vertices is important to identify the hard scattering process and to measure the amount of pile-up interactions, while the reconstruction of so called secondary vertices is an important ingredient in the identification of jets originating from bottom quarks. The latter, referred to as b-tagging, is of great use in many high-profile physics analyses in e.g. the top quark, Higgs and new phenomena sectors to suppress background processes containing predominantly light-flavour jets. Performance of alignment, track and vertex reconstruction efficiency and resolution achieved in the 2011 and prospects for the 2012 LHC proton-proton collision runs will be discussed. We will present measurements of the b-tag efficiency carried out with jets containing muons as well as with b-jets from top quark decays. A novel measurement of the efficiency to b-tag jets originating from c-quarks, using a sample of jets containing D* mesons, will also be presented as well as two complementary measurements of the rate with which jets originating from light-flavour partons are mistakenly tagged as b-jets.
Speaker: Dr Mark James Tibbetts (Lawrence Berkeley National Laboratory (US))
• 12:00
Performance of Jets and Missing Transverse Energy in CMS 15m
A summary of the measurements of the jet energy calibration in CMS is presented, performed with data samples collected in proton-proton collisions at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 1.6/fb. The final jet energy calibration is based on dijet, γ+jet and Z+jet events. The results are presented for the "Particle Flow" approach, which attempts to reconstruct individually table particles in the event, prior to the jet clustering, based on information from all relevant subdetectors. We discuss the effect of pile-up interactions and the state of the art mitigation techniques used in CMS and we describe the main sources of uncertainty on the jet energy calibration. Finally, the results of comprehensive studies of missing transverse energy are presented.
Speaker: Mr Joram Berger (KIT (DE))
• 12:15
Performance of Jets and Missing Transverse Energy in ATLAS 15m
After the analysis of the 2010 proton proton collision data provided by LHC, the ATLAS experiment has achieved an accuracy of the jet energy measurement between 2-4% for jet transverse momenta from 20 GeV to about 2 TeV in the pseudo-rapidity range up to |eta|=4.5. The jet energy scale uncertainty is derived from in-situ single hadron response measurements along with systematic variations in the Monte Carlo simulation. In addition, several in situ techniques exploiting transverse momentum balance are exploited. Preliminary results from the 2011 run based on an integrated luminosity of 5/fb reducing further the uncertainties on the jet energy scale will also be presented. Results on the energy scale and resolution of the reconstructed missing transverse momentum (ETmis) from 2010 and 2011 collision data will be presented. The uncertainty evaluation mainly relies on events with a Z-boson. Special attention will be given to the influence of the large number of interactions produced in addition to the event of interest (pile-up). Techniques to mitigate pile-up effects for jets and ETmiss will be discussed. Advanced approaches to jet reconstruction using jet grooming algorithms such as filtering, trimming, and pruning are compared. Such techniques aim to reconstruct the jet mass and jet substructure with special focus on highly boosted particles
Speaker: Prof. Ariel Gustavo Schwartzman (SLAC National Accelerator Laboratory (US))
• 12:30
Development and Construction of Muon Drift-Tube (sMDT) Chambers for Upgrades of the ATLAS Muon Spectrometer at High LHC Luminosities 15m
For the planned high-luminosity upgrades of the Large Hadron Collider (LHC)increasing background rates of neutrons and gamma rays are expected exceed the rate capability of the current ATLAS muon tracking detectors. Drift-tube chambers with a tube diameter of 15 mm have (sMDT chambers) been developed for upgrades of the ATLAS muon spectrometer. A full sMDT prototype chamber has been constructed and tested in a muon beam at CERN and at high gamma and proton irradiation rates. The chamber design and construction procedures are discussed. The test results demonstrate the required track reconstruction efficiency and spatial resolution of the sMDT chambers at background rates far beyond the maximum expected values. The sense wire locations in the prototype chamber have been measured with few micron precision with cosmic rays confirming the required wire positioning accuracy of better than 20 microns. Currently sMDT chambers are under construction for installation in the ATLAS muon spectrometer in the 2013/14 LHC shutdown. Further sMDT chamber construction for subsequent upgrades are in the planning phase. New readout electronics for the chambers with higher bandwidth and better radiation hardness is also under development.
Speaker: Dr Hubert Kroha (Max-Planck-Institut für Physik (DE))
• 12:45
Exploring physics beyond the Standard Model with a Muon Acceleration Facility 15m
An accelerator complex that can produce ultra-intense beams of muons presents many opportunities to explore new physics. A facility of this type is unique in that, in a relatively straightforward way, it can present a physics program that can be staged and thus move forward incrementally, addressing exciting new physics at each step. An intense cooled low-energy muon source can be used to perform extraordinarily precise lepton flavor violating experiments. These same muons can be accelerated and then stored in a race track-like storage ring to produce neutrinos for experiments to explore neutrino mixing with unprecedented precision, creating the so-called Neutrino Factory. Finally, these muons could be accelerated to very-high energy to do energy-frontier physics with a muon collider. In this talk I will give an introduction to muon accelerator facilities and their physics capabilities and then will discuss some of the limiting technologies that must be developed in order to make these concepts a reality and the US Muon Accelerator Program that aims to address these technical challenges.
Speaker: Prof. Donald Hartill (Cornell University (US))
• 13:00
Lunch Break 1h
• 14:00
Performance of the CMS Level-1 Trigger 20m
The first level trigger of the CMS experiment is comprised of custom electronics that process data from the calorimeters and muon detectors in order to select the most interesting events from LHC collisions. The rate of events selected by this Level-1 trigger must be reduced from the beam crossing frequency to no more than 100 kHz before detector digitization and High Level Trigger processing can occur. Here we report on the efficiencies, resolution, and trigger rates of the Level-1 trigger as measured from LHC proton collisions at 7 and 8 TeV center-of-mass energies. Example trigger menus used to select events for physics analysis by the CMS experiment also will be discussed.
Speaker: Dr Jim Brooke (University of Bristol (UK))
• 14:20
The ATLAS Trigger Performance and Evolution 20m
During the data taking period from 2009 until 2011, the ATLAS trigger has been very successfully used to collect proton-proton data at LHC centre-of-mass energies between 900 GeV and 7 TeV. The three-level trigger system reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of about 300 Hz. Using custom electronics with input from the calorimeter and muon detectors, the first level rejects most background collisions in less than 2.5 microseconds. Then follow two levels of software-based triggers. The trigger system is designed to select events by identifying muons, electrons, photons, taus, jets and B hadron candidates, as well as using global event signatures, such as missing transverse energy. We give an overview of the strategy and performance of the different trigger selections based mainly on the experience during the 2011 LHC run, where the trigger menu needed quick adaptations to the continuous increase of luminosity throughout the year. Examples of trigger efficiencies and resolution with respect to offline reconstructed signals are presented and compared to simulation. These results illustrate that we have achieved a very good level of understanding of both the detector and trigger performance and successfully selected suitable streamed data samples for analysis. Furthermore, we describe how the trigger selections and overall trigger menu (like adding topological triggers, using isolation or using multi-variate techniques) have been re-designed and re-optimized to cope with the increased center-of-mass energy and pileup conditions foreseen in 2012. Initial experience and performance of the trigger running with 8 TeV center-of-mass energy collisions this year will also be described.
Speaker: Dr Brian Petersen (CERN (CH))
• 14:40
The CMS High Level Trigger 15m
The CMS experiment has been designed with a 2-level trigger system: the Level 1 Trigger, implemented using FPGA and custom ASIC technology, and the High Level Trigger (HLT), implemented running a streamlined version of the CMS offline reconstruction software on a cluster of commercial rack-mounted computers, comprising thousands of CPUs. The design of a software trigger system requires a tradeoff between the complexity of the algorithms running online, the output rate, and the selection efficiency. The complexity is limited by the available computing power, while the rate is constrained by the offline storage and processing capabilities. The main challenge faces during 2012 is the fine-tuning and optimisation of the algorithms, in order to cope with the increasing LHC pile-up without impacting the physics performance. Here we will present a review of the performance of the main triggers uses during the 2012 data taking, ranging from simpler single-object selections to more complex algorithms combining different objects, and applying analysis-level reconstruction and selection. We will discuss how the increasing LHC pile-up is affecting their performance, and how these effects is being mitigated.
Speaker: Dr Stéphanie Beauceron (Universite Claude Bernard-Lyon I (FR))
• 14:55
The ATLAS Data Acquisition and High Level Trigger Systems: Experience and Upgrade Plans 15m
The ATLAS DAQ/HLT system reduces the Level 1 rate of 75 kHz to a few kHz event build rate after Level 2 and a few hundred Hz out output rate to disk. It has operated with an average data taking efficiency of about 94% during the recent years. The performance has far exceeded the initial requirements, with about 5 kHz event building rate and 500 Hz of output rate in 2012, driven mostly by physics requirements. Several improvements and upgrades are foreseen in the upcoming long shutdowns, both to simplify the existing architecture and improve the performance. On the network side new core switches will be deployed and possible use of 10GBit Ethernet links for critical areas is foreseen. An improved read-out system to replace the existing solution based on PCI is under development. A major evolution of the high level trigger system foresees a merging of the Level 2 and Event Filter functionality on a single node, including the event building. This will represent a big simplification of the existing system, while still maintaining the flexibility of the Region of Interest based approach. It will furthermore open up new optimizations and simplifications in the existing HLT code.
Speaker: Dr Reiner Hauser (Michigan State University (US))
• 15:10
Evolution of the CMS Trigger System 15m
A key challenge at high luminosity hadron colliders is the selection of sufficiently pure event samples against large QCD backgrounds, whilst keeping data rates within practical bounds. The CMS trigger system performs the first step in event selection, and its performance dictates the physics reach of the experiment in many areas. As LHC luminosity continues to increase over the next decade, both the trigger strategy and systems must evolve. We describe the upgrade plans for the CMS trigger, including the possible use of tracking information at level-1, and explore the impact for the high-luminosity physics programme.
Speaker: Dr Ivan Kresimir Furic (University of Florida (US))
• 15:25
Upgrade project and plans for the ATLAS detector and first level trigger. 15m
In the coming years, the LHC complex will be upgraded to extend the physics potential of the experiments. The average luminosity will be increased by a factor 5 to 10 above the original design one. The planned upgrades require, among other detector and DAQ system improvements, a significant higher selectivity of the trigger system, to cope with the increased radiation level and particle rates. In this paper we describe the changes to the ATLAS detector and its trigger system currently under study. The calorimetry--‐based trigger detectors will improve their selectivity by benefiting from the increased granularity available at the trigger level, which will allow for a higher energy resolution. In the muon detector, the momentum resolution of the trigger can be improved by using the precision muon tracking detectors, the Monitored Drift Tuber chambers (MDT). An MDT--‐based trigger scheme has been developed and validated, based on new radiation--‐hard readout chips currently under development. The use of the inner tracking system in the lower levels of the trigger selection is also discussed. While the second level trigger will be helped by a new fast tracking system, the addition of tracking information at the first level trigger during the last phase of the LHC upgrade is currently under discussion. Different scenarios are compared, having in mind the requirements to achieve the expected physics potential of ATLAS in this high luminosity regime.
Speaker: Dr Mimmo Della Volpe (Università "Federico II" di Napoli & INFN (IT))
• 15:40
Refreshment Break 20m
• 16:00
The LHCb upgrade 20m
The LHCb experiment is designed to perform high-precision measurements of CP violation and search for New Physics using the enormous flux of beauty and charmed hadrons produced at the LHC. The operation and the results obtained from the data collected in 2010 and 2011 demonstrate that the detector is robust and functioning very well. However, the limit of ~1 fb-1 of data per year cannot be overcome without improving the detector. We therefore plan for an upgraded spectrometer by 2018 with a 40 MHz readout and a much more flexible software-based triggering system that will increase the data rate as well as the efficiency specially in the hadronic channels. Here we present the LHCb detector upgrade plans.
Speaker: Prof. Franz Muheim (University of Edinburgh (UK))
• 16:20
ATLAS Upgrades Towards the High Luminosity LHC: extending the discovery potential 15m
After successful LHC operation at 7 TeV in 2011, the LHC is scheduled to deliver even more data in 2012. Meanwhile, plans are actively advancing for a series of upgrades, culminating roughly 10 years from now in the high luminosity LHC (HL-LHC) project, delivering of order five times the LHC nominal instantaneous luminosity along with luminosity levelling. The final goal is to extend the data set from about 300 fb-1 expected for LHC running to 3000 fb-1 by around 2030. Current planning in ATLAS also has significant upgrades to the detector during the consolidation of the LHC to reach full LHC energy and further upgrades to accommodate running already beyond nominal luminosity this decade. The challenge of coping with HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requires further major changes to the ATLAS detector. The designs are developing rapidly for an all-new inner-tracker, significant upgrades in the calorimeter and muon systems, as well as improved triggers and data acquisition. This presentation summarises the various improvements to the ATLAS detector required to cope with the anticipated evolution of the LHC instantaneous luminosity during this decade and the next.
Speaker: Dr Markus Elsing (CERN (CH))
• 16:35
Status and Plans for the Upgrades of the CMS Detector 15m
The LHC has successfully delivered more than 12 /fb of data through operations from 2009-2012, which CMS has used for wide range of physics analyses. CMS is planning a set of detector upgrades beginning in 2013 and continuing to support physics in the HL-LHC era, which will extend the delivered luminosity up to 3000 /fb by 2030. The projects already in the technical design phase in planned improvements include an improved pixel tracker, enhancements to the hadronic calorimeters, and a more-powerful Level-1 trigger. For HL-LHC, designs for a trigger-capable tracker and extremely radiation-hard forward calorimeters are under study. This presentation summarizes the various improvements to the CMS detector planned to optimize the physics yield from LHC data over the next 20 years.
Speaker: Prof. Jeremy Mans (University of Minnesota (US))
• 16:50
Overview of the ATLAS Insertable B-Layer (IBL) Project 15m
The upgrades for the ATLAS Pixel Detector will be staged in preparation for high luminosity LHC. The first upgrade for the Pixel Detector will be the construction of a new pixel layer which will be installed during the first shutdown of the LHC machine, foreseen in 2013-14. The new detector, called the Insertable B-layer (IBL), will be installed between the existing Pixel Detector and a new, smaller radius beam-pipe at a radius of 3.3 cm. The IBL will require the development of several new technologies to cope with increased radiation and pixel occupancy and also to improve the physics performance through reduction of the pixel size and a more stringent material budget. Two different and promising silicon sensor technologies, planar n-in-n and 3D, are currently under investigation for the IBL. An overview of the IBL project, of the module design and their qualification with particular emphasis on irradiation tests will be presented.
Speaker: Dr Mario Giordani (INFN Trieste (IT))
• 17:05
The status of the CMS pixel upgrade detector 15m
The present CMS pixel detector was designed for a maximum luminosity of 1×1034 cm−2s−1. Following the Phase 1 upgrade of the LHC, the peak luminosity is foreseen to reach 2×1034 cm−2s−1. Due to the radiation damage and large data losses in the readout chip the present pixel system must be replaced by a new one in the long shutdown of 2016. The current status of the CMS pixel detector upgrade project will be presented. The new features of the proposed detector that will be discussed are ultra-light mechanical design with four barrel layers and 3 end-cap disks, digital readout chip with higher rate capability and new cooling system.
Speaker: Mr Ferdinando Giordano (University of California Riverside (US))
• 17:20
Precision tracking at high background rates with the ATLAS muon spectrometer 15m
The ATLAS muon spectrometer performs to the specs of efficiency, occupancy and spatial resolution at present LHC peak-luminosities of $4 \times 10^{33}$ $\frac{1}{cm^2~s}$. Ten times higher peak-luminosities are envisaged after the LHC upgrade by end of this decade. Currently used tracking detectors in the most forward part of the muon spectrometer need to be replaced to cope with the expected huge background hit rates of up to 15~kHz/cm$^2$ to ensure muon trigger and precision reconstruction capabilities. Square meter sized micromegas or 15~mm diameter drift-tube detectors together with thin gap trigger detectors are under study as replacement. When exposed at our irradiation facility at the Garching Tandem accelerator laboratory, the track reconstruction efficiency and spatial resolution of 15~mm drift-tube detectors is robust against up to 20~kHz/cm$^2$ highly ionizing background hits. No signs of ageing were observed after accumulating an irradiation dose corresponding to 10 years of high luminosity LHC operation. For the micromegas detectors, which are intrinsically high rate capable, a single hit spatial resolution of 40~$\mu$m has been shown. Micromegas using resistive strip technology have been successfully operated unter $10^7$ Neutrons$/cm^2~s$ of 11~Mev. For the central part of the muon spectrometer, the installed monitored 30~mm diameter drift-tube detectors remain in place but may be operated using a considerably faster and linear drift-gas mixture. Such gas mixtures have been shown to be marginally sensitive to high photon fluences and do not age due to ionizing radiation.
Speaker: Dr Ralf Hertenberger (Ludwig-Maximilians-Univ. München (DE))
• 17:35
Performance and Upgrade plans for the CMS Hadron Calorimeter at the LHC 15m
The hadron calorimeters of the CMS experiment have successfully recorded data at 7 TeV and 8 TeV center-of-mass energy during 2011 and 2012 LHC operation. The performance of all systems (barrel, end-cap, forward and the outer calorimeters) are discussed and results from the full 2011 dataset are shown on noise rejection, calibration, collision timing, and identification of jet candidates and for other salient features. In addition, the CMS collaboration is planning improvements to the hadron calorimeters which include the replacement of the HPD photodetectors with SiPMs, increased depth segmentation in the calorimeter, and the inclusion of TDC capability. The status of the R&D for these upgrades will be discussed, including the testing of the upgraded microTCA readout electronics during current LHC data taking.
Speaker: Dr Sudarshan Paramesvaran (University of California Riverside (US))
• 17:50
Radiation-Hard High-Speed Parallel Optical Links 15m
We have designed two ASICs for possible applications in the optical links of a new layer of the ATLAS pixel detector for the initial phase of the LHC luminosity upgrade. The ASICs include a high-speed driver for a VCSEL and a receiver/decoder to extract the data and clock from the signal received by a PIN diode. Both ASICs contain 12 channels for operation with a VCSEL or PIN array. Among these channels, the outer four channels are designated as spares to bypass a broken PIN or VCSEL within the inner eight channels. The ASICs were designed using a 130 nm CMOS process to enhance the radiation-hardness. With the spacing of 250 μm between two VCSEL or PIN channels, the width of an optical array is only 3 mm. This allows the fabrication of compact parallel optical engine for installation at a location where space is at a premium. The fabricated receiver/decoder properly decodes the bi-phase marked input stream with no bit error at low PIN current. The performance of the VCSEL driver at 5 Gb/s is satisfactory. We are able to program the ASICs to bypass a broken PIN or VCSEL and the power-on reset circuits have been successfully implemented to set the ASICs to a default configuration in an event of communication failure. We have irradiated the receiver/decoder to high dose and observe no significant degradation and the SEU rate is low. We plan to irradiate the VCSEL drivers in the summer to measure the radiation hardness. We will present results from the study at the conference. In addition, we will briefly present the status of the design of a new VCSEL driver ASIC to operate at 10 Gb/s which will yield an aggregated bandwidth of 120 Gb/s for a fiber ribbon.
Speaker: Prof. Kock Kiam Gan (Ohio State University (US))
• 09:00 18:00
Room 219 - Beyond the Standard Model SUSY / Non-SUSY - TR2&3 Room 219

### Room 219

#### Melbourne Convention and Exhibition Centre

Melbourne Australia
• 09:00
Natural Supersymmetry 15m
The non-observation of signals for supersymmetry in the LHC data appears to have led to questions about the viability of supersymmetry in nature. We delineate clear criteria for SUSY models which stabilize the electroweak scale, and show that these models are not in conflict the non-appearance of SUSY in the 2011 LHC data. Finally, we discuss some phenomenological implications of these Natural SUSY scenarios.
Speaker: Prof. Xerxes Tata (University of Hawaii (US))
• 09:15
GUT-less mSUGRA 15m
In this talk we consider the phenomenology of minimal supergravity (mSUGRA) models in which the supersymmetry-breaking parameters are unified at a scale below the GUT scale. After a brief review of the so-called GUT-less constrained MSSM (CMSSM), we turn to a GUT-less version of mSUGRA. Of particular interest are GUT-less Polonyi models. The possibility that the recent ATLAS and CMS results may be compatible with a Standard Model-like Higgs boson with a mass of approximately 125 GeV is addressed. The dark matter candidate may be either the gravitino or the lightest neutralino. In the latter case, we discuss the prospects for direct detection via elastic scattering on nuclei.
Speaker: Ms Pearl Sandick (University of Utah (US))
• 09:30
Higgs boson mass in GMSB with messenger-matter mixing 15m
In minimal models of gauge mediated SUSY breaking the mass of the lightest neutral Higgs boson cannot exceed about 118 GeV, provided that the SUSY particle masses are below 2 TeV. This work investigates the Higgs boson mass in the presence of messenger--matter mixing. Such mixing would generate a non-zero A-term (trilinear soft SUSY braking term) at the messenger scale, which enhances the Higgs mass to about 126 GeV, even when all superparticle masses are below a TeV. Such a spectrum is shown to be consistent with recent LHC limits. The increase in m_h is maximal in the case of messengers belonging to 10+10* of SU(5). The embedding of these models in SU(5), along with a flavor U(1) symmetry, addresses the fermion mass hierarchy problem and generates naturally large neutrino mixing angles, while being consistent with all flavor changing processes.
Speaker: Prof. Kaladi S. Babu (Oklahoma State University (US))
• 09:45
Implications of a SM like Higgs for a natural NMSSM with low cutoff 15m
We will present a study of the NMSSM with a low cutoff in the light of the recent experimental hints for a (close to) SM like Higgs at 125 GeV. The introduction of a singlet with a large value of lambda reduces the fine tuning in comparison to the MSSM and provides a solution to the mu-problem. We determine the natural region in parameter space with a fine tuning better than 10% which satisfies electroweak constraints and study its implications for phenomenology.
Speaker: Dr Michael Schmidt (University of Melbourne (AU))
• 10:00
SUSY Without Prejudice at LHC-7 & -8 15m
We will examine the capability of the 7/8 TeV LHC to explore the 19(20) dimensional parameter space of the pMSSM SUSY model following the ATLAS MET analysis suite. Allowing for either a neutralino or gravitino LSP and assuming all sparticle masses lie below 4 TeV, we demonstrate that the LHC searches can cover a large fraction of this space. The importance of non-MET searches, such as those for heavy stable charged particles, $A\to \tau \tau$ and $B_s \to \mu\mu$ will also be discussed.
Speaker: Dr Thomas Rizzo (SLAC (US))
• 10:15
A 125 GeV Higgs in the PQ violating minimal Supergravity model 15m
Motivated by the recent hints from ATLAS and CMS we consider a minimal supersymmetric model which, due to its approximate Peccei-Quinn symmetry, naturally accommodates a 125 GeV Higgs boson. This model can also explain the potentially anomalous branching ratios of such a Higgs. We examine whether other experimental evidence supports this scenario.
Speaker: Dr Sudhir Kumar Gupta (Monash University (AU))
• 10:30
Refreshment Break 30m
• 11:00
Flavour violating squark and gluino decays at LHC 15m
We study the effect of squark generation mixing on squark and gluino production and decays at LHC in the Minimal Supersymmetric Standard Model (MSSM) with focus on mixing between second and third generation squarks. Taking into account the constraints from B-physics we show that various regions in parameter space exist where decays of squarks and/or gluinos into flavour violating final states can have large branching ratios of up to ~ 40%. Here we consider both fermionic and bosonic final states. Rates of the corresponding signals, e.g. pp -> t t cbar cbar missing-E_T X, can be significant at LHC(14 TeV). We find that the inclusion of flavour mixing effects can be important for the search of squarks and gluinos and the determination of the underlying model parameters of the MSSM. (A part of this work is published in Phys. Rev. D84 (2011) 115026; arXiv:1107.2775 [hep-ph].)
Speaker: Prof. Keisho Hidaka (Tokyo Gakugei University (JP))
• 11:15
Illuminating the 130 GeV Gamma Line with Continuum Photons 15m
There is evidence for a 130 GeV $\gamma$-ray line at the Galactic Center in the \emph{Fermi} Large Area Telescope data. Dark matter candidates that explain this feature should also annihilate to Standard Model particles, resulting in a continuous spectrum of photons. To study this continuum, we analyze the \emph{Fermi} data down to 5 GeV, restricted to the inner $3^\circ$ of the Galaxy. We place a strong bound on the ratio of continuum photons to monochromatic line photons that is independent of uncertainties in the dark matter density profile. Neutralino dark matter is excluded by the derived constraints.
Speaker: Prof. Jacob Wacker (SLAC (US))
• 11:30
Searches for long-lived particles with the ATLAS detector 15m
Several extensions of the Standard Model predict the existence of massive long-lived particles. We report on searches for weakly-interacting long-lived particles decaying to collimated lepton-jets far away from the interaction point, and for production of highly-ionizing magnetic monopoles. The talk presents results of analyses using data recorded in 2011 at sqrt(s)=7 TeV centre-of-mass energy by the ATLAS experiment at the LHC
Speaker: Dr Andrew Haas (New York University)
• 11:45
Search for Charged Massive Long-Lived Particles 15m
We report on a search for charged massive long-lived particles (CMLLPs), based on data collected with the D0 detector at the Fermilab Tevatron ppbar collider. We search for events in which one or more particles are reconstructed as muons but have speed and ionization energy loss (dE/dx) inconsistent with muons produced in beam collisions. CMLLPs are predicted in several theories of physics beyond the standard model. We present limits on massive long-lived particles in several supersymmetric theories.
Speaker: Prof. Yuri Gershtein (Rutgers University (US))
• 12:00
Search for new massive stable particles at CMS 15m
Several models of new physics, including split supersymmetry, predict the existence of heavy particles which are long-lived on timescales of the bunch spacing of the LHC. We present the results three dedicated searches using the measurement of the energy loss dE/dx in the tracking system, the time-of-flight and special jet triggers. The full sample of 5 fb-1 of pp collisions recorded with CMS in 2011 at the center-of-mass-energy of 7 TeV has been used
Speaker: Dr Fedor Ratnikov (KIT (DE))
• 12:15
Search for new physics with displaced leptons, jets, and photon at CMS 15m
We present results of searches for new long-lived particles with a distinctive signature of decay products far from the primary event vertex. Dedicated trigger and reconstruction algorithms have been developed to identify such displaced particles. The full sample of 5 fb-1 of pp collisions recorded with CMS in 2011 at the center-of-mass energy of 7 TeV has been used.
Speaker: Prof. Valerie Halyo (Princeton University (US))
• 12:30
A Seiberg Dual for the MSSM: Partially Composite W and Z 20m
We examine the possibility that the SU(2) gauge group of the standard model appears as the dual "magnetic" gauge group of a supersymmetric gauge theory, thus the W and Z (and through mixing, the photon) are composite (or partially composite) gauge bosons.
Speaker: Prof. Yuri Shirman (University of California Irvine)
• 12:50
Lunch Break 1h 10m
• 14:00
Searches for vector-like quarks with the ATLAS detector 15m
Various extensions of the Standard Model predict the existence of new types of quarks. We report on several search channels such as vector-like quarks that couple to light quarks and Z or W bosons or new quarks decaying to Z boson and b quark. The talk presents results from searches for vector like quarks using the data sample recorded in 2011 at sqrt(s)=7 TeV centre-of-mass energy by the ATLAS experiment at the LHC.
Speaker: Mr Merlin Davies (Universite de Montreal (CA))
• 14:15
4th generation searches at ATLAS 15m
The top-quark is the heaviest known fundamental particle with unique properties within the Standard Model. Its large couplings to the Higgs boson, and being the only quark that decays before hadronisation make it sensitive to new physics beyond the SM. A potential extension for the SM would be the adjonction a 4th family of heavy chiral fermions that could provide new sources of CP violation to explain the matter-antimatter asymmetry in the Universe, and allow for a heavier Higgs boson while remaining consistent with other precision electroweak studies. We report on searches for 4th generation quarks using the data sample recorded in 2011 at sqrt(s)=7 TeV centre-of-mass energy by the ATLAS experiment at the LHC.
Speaker: Dr Lorenzo Feligioni (Universite d'Aix - Marseille II (FR))
• 14:30
Search for 4th generation quarks 15m
We present results of searches for a new heavy 4th generation quark using leptonic, semileptonic and hadrnic final states.The full sample of 5 fb-1 of pp collisions recorded with CMS in 2011 at the center-of-mass energy of 7 TeV has been used.
Speaker: Dr Sadia Khalil (Kansas State University (US))
• 14:45
Bootstrap Dynamical Symmetry Breaking with New Heavy Chiral Quarks 15m
Despite the hint for a 125 GeV Higgs boson, we consider the other option of MH > 600 GeV, noting that the existence of the Higgs boson itself is not yet an established fact. What we do know is that the Goldstone bosons of electroweak symmetry breaking exist as longitudinal components of the weak bosons. The Goldstone boson coupling to a new heavy chiral quark doublet Q (assuming it exist), the G-Q-Q(bar) Yukawa coupling, would now be in the strong coupling regime, given the LHC limit of MQ > 600 GeV is already beyond the perturbative partial-wave unitarity bound. Such strong Yukawa couplings could induce Q-Q(bar) condensation, which might take the role of the Higgs condensate. Guided by a Bethe-Salpeter equation approach, we identify the leading "collapsed state", the (heavy) isotriplet, color singlet "meson", as the Goldstone boson G itself. Viewing G as a very deeply bound state, a "bootstrap" gap equation without a Higgs particle is constructed. Electroweak symmetry breaking via strong Yukawa coupling generates both heavy mass for Q, while self-consistently justifying the keeping of G as a massless Goldstone particle in the loop. We solve such a gap equation, and investigate the mass of heavy quarks in this bootstrap picture, which is found to be not less than a TeV. We consider also a scale-invariant model by Hung and Xiong, in which a massless scalar doublet phi couples strongly with Q, which induces electroweak symmetry breaking. Although a gap equation similar to the one in the bootstrap picture can be written down, we discuss differences with the results of Hung and Xiong, as well as offer a brief critique.
Speaker: Prof. George Wei-Shu Hou (National Taiwan University (TW))
• 15:00
Searches for New Physics with CDF Detector 15m
Searches for physics beyond the standard model are intensively pursued using the full CDF Run II sample. Many among them are pursued in the top-quark sector because it is believed that the top-quark, due to its very large mass, may play a special role in the spontaneous breaking of the electroweak symmetry of the standard model as well as in possible new physics. We present searches for a heavy Z' boson decaying into a top-quark pair in the semi-leptonic decay channel as well as in semi-leptonic decays associated with one and two additional jets; a search for a dark matter candidate particle associated with a single top-quark decaying into the neutrino+jets decay channel and a search of a dark matter candidate particle in events with one jet and large missing transverse energy; and a search for new physics in events with a delayed photon and large missing transverse energy.
Speakers: Mr Adam Aurisano (Texas A&M University), Adam Aurisano (Unknown), Adam Jude Aurisano
• 15:15
LHC Signatures Inspired by Yukawa-bound Mesons: Double Resonant WW+jet 15m
With 5 fb^{-1} LHC data at 7 TeV collected in 2011, current mass limits of the chiral 4th generation quarks have reached 600 GeV, nominally entering the regime of perturbative unitarity violation. The very large Yukawa couplings of these quarks may require nonperturvative treatment, including the possible formation of tightly Yukawa-bound "mesons". Assuming an almost degenerate 4th generation quark doublet (heavy Isospin) and large Higgs-boson mass as required to be consistent with the electroweak precision observables, the spectrum of Yukawa-bound mesons would likely be M(pi_1) < [M(pi_8), M(omega_1)] < M(omega_8), where pi and omega copy from isospin notation, while 1 and 8 in subscript reflect the color of these mesons. The leading production is q\bar{q} --> omega_8, with a rather rich decay phenomenolgy. A possible "double resonance" final state appears where omega_8 decays predominantly into a pi_8 plus a weak boson, followed by the decay of the pi_8 into a weak boson plus a gluon. This unusual final state is realized when the mixing of 4th generation quarks with SM quarks is small, which is consistent with absence of new physics signals from flavor physics. We perform a phenomenological study for the signature at the LHC using the W-jet tagging method, including SM background estimation and demonstration of resonance mass determination. This study also serves as a precursor study for the search for other resonances with the same final state, such as technicolor models with QCD-colored techniquarks.
Speaker: Dr Hiroshi Yokoya (National Taiwan University (TW))
• 15:30
Refreshment Break 30m
• 16:00
Up-to-date results and upgrade plans of the MEG experiment 15m
The MEG experiment at the Paul Scherrer Institut (Switzerland) aims at searching for the Lepton-Flavour Violating (LFV) muon decay, mu+ -> e+ gamma, with unprecedented sensitivity. Such decay is forbidden within the Standard Model, nevertheless all its viable extensions predict a branching ratio for this decay in the 10^{-14} to 10^{-12} range. Data collected in 2009 and 2010, which corresponds to a total of 1.8x10^{14} muon decays, allowed us to set the most stringent limit to date on charged LFV (BR(mu->e gamma < 2.4x10{-12} at 90% C.L.). The status of the experiment during the last data taking will be presented together with preliminary analysis of 2011 data. In parallel with the data-taking, the MEG collaboration has recently started to discuss the upgrade plan in order to perform the experiment with three times higher beam intensity and better measurement resolutions, and already started several associated R&D. In addition to the future prospects, the detailed studies of upgrade will also be presented.
Speaker: Dr Hajime Nishiguchi (KEK (JP))</