ICHEP 2010

Europe/Paris
Palais des Congrès de Paris

Palais des Congrès de Paris

2 place de la Porte Maillot Paris 17
Description

 

 

The French particle physics community is particularly proud to have been selected to host the 35th ICHEP conference in 2010 in Paris. This conference is the focal point of all our field since more than fifty years and is the reference event where all important results in particle physics cosmology and astroparticles are presented and discussed. This alone sufficed to make this event very important. But in 2010, a coincidence of exceptional events made this conference even more attractive! What is then so special about ICHEP 2010 conference? It was the first ICHEP conference where physics results obtained at the LHC were presented! New results about the elusive Higgs boson, or signals of physics beyond the standard model were therefore expected at this conference! Major discoveries in other domains such as gravitational waves, neutrino telescopes, neutrino oscillations, dark matter or in the flavour sector were also possible, just to name a few.

In addition , 2010 is an important date to shape up the future of our field. Several major projects presented the status of their Conceptual or Engineering Design Reports during the conference. The International Linear Collider (ILC) Global Design Effort team presented the report corresponding to the end of their Technical Design Phase 1. The Compact Linear Collider (CLIC) also reported on its Conceptual Design Report. Other major projects such as Super B factories were also presented. These reports together with LHC physics results will form the basis for key political decisions needed to be taken in the years to come.

In summary, there can be no doubt that Paris was the place to be in summer 2010 for anyone interested in High Energy Physics and we made every effort to make your stay as interesting and enjoyable as possible.

The next ICHEP conference, ICHEP2012, will take place in Australia.

    • 08:00 09:00
      Registration 1h
    • 09:00 10:30
      01 - Early Experience and Results from LHC Salle Maillot ()

      Salle Maillot

      Convener: Guenther Dissertori (Institut fur Teilchenphysik)
      • 09:00
        Optimisation of LHC beam conditions 20m
        We report on the monitoring and optimization of the beam conditions in early LHC operation : luminosity monitoring, optimization and calibration, beam-spot size and position and machine induced backgrounds
        Speaker: Dr. Helmut Burkhardt (CERN)
        Slides
        Video
      • 09:25
        Determination of the Luminosity by the LHC Experiments 15m
        The high resolution of the LHCb vertex detector allows for precise measurements of vertex positions of beam-gas and beam-beam interactions. From these measurements beam parameters such as width and position can be inferred. A novel method will be presented for determining the absolute luminosity at the LHC using these directly measured beam parameters, in combination with beam intensity information provided by the accelerator. Results will be shown for both the 2009 and 2010 run, and prospects for the ultimate precision of this method will be discussed. A forward look will also be given to alternative methods of luminosity determination which with data samples of ~1 fb−1 will offer the possibility of ~1% level precision. These include measurements of the production rate of elastic two photon dimuon production, and studies based on W and Z production in the forward region. In addition, luminosity measurements at ATLAS and CMS will also be discussed.
        Speaker: Massimiliano Ferro-Luzzi (CERN)
        Slides
        Video
      • 09:45
        Performance of the ATLAS Trigger with Proton Collisions at the LHC 13m
        The ATLAS trigger has been used very successfully to collect collision data during 2009 and 2010 LHC running at centre of mass energies of 900 GeV, 2.36 TeV, and 7 TeV. The trigger system reduces the event rate, from the design bunch‐crossing rate of 40 MHz, to an average recording rate of 200Hz. The ATLAS trigger is composed of three levels. The first (Level 1) uses custom electronics to reject most background collisions, in less than 2.5μs, using information from the calorimeter and muon detectors. The upper two trigger levels, known collectively as the High Level Trigger (HLT), are software‐based triggers. As well as triggers using global event features, such as missing transverse energy, there are selections based on identifying candidate muons, electrons, photons, tau mesons or jets. We give an overview of the performance of these trigger selections based on extensive online running during LHC collisions and describe the progress towards fully commissioning these triggers. Distributions of key selection variables based on calorimeter and tracking information are shown calculated at the different trigger levels and are compared with offline reconstruction. We include examples of online triggering of Standard Model physics such as candidate W‐boson decays. Comparisons between data and simulations are shown for some important selection variables, already illustrating a very good level of understanding of the detector and trigger performance. We describe how the trigger has evolved with increasing LHC luminosity and give a brief overview of plans for forthcoming LHC running.
        Speaker: John Baines (Particle Physics-Rutherford Appleton Laboratory-STFC - Science &)
        Slides
        Video
      • 10:00
        Performance of the CMS High-Level Trigger 13m
        The CMS trigger system has been designed to cope with unprecedented luminosities and accelerator bunch-crossing rates of up to 40 MHz at LHC. The High-Level-Trigger (HLT) combines in a novel way the traditional L2 and L3 trigger components which are implemented in a commercial Filter Farm with thousands of CPUs. The flexibility of a contiguous software environment allows the coherent tuning of the HLT algorithms to accommodate multiple physics channels and enhance the CMS physics reach. We will report on the trigger commissioning of the HLT with the first LHC pp collisions at 900 GeV, 2.36 TeV and 7 TeV and discuss the first results on the trigger performance.
        Speaker: Edgar Fernando Carrera Jarrin (Boston University-Unknown-Unknown)
        Slides
        Video
      • 10:15
        LHCb trigger system 13m
        The Large Hadron Collider beauty experiment (LHCb) is a dedicated heavy flavour physics experiment at the LHC. The trigger system employs the finite lifetime and relative large mass of charm and beauty hadrons to distinguish heavy flavour and background from inelastic pp-scattering. The LHCb trigger is a two level system. The first level is implemented in hardware, it reduces the visible interaction rate to a maximum of 1MHz, at which the whole detector can be readout. The second trigger level is a C++ application running on an Event Filter Farm composed of several thousand CPU nodes. The full trigger is operational in the experiment. In this talk, an overview of the LHCb trigger system will be given. We put special emphasis on the experience obtained with the initial data taking at the LHC, and the commissioning and monitoring of the software trigger. The method to obtain the efficiency of the trigger from real data will be described, and first results will be presented.
        Speaker: Eric Van Herwijnen (CERN)
        Slides
        Video
    • 09:00 10:30
      02 - The Standard Model and Electroweak Symmetry Breaking Salle 252B ()

      Salle 252B

      Convener: Prof. Stefan Dittmaier (Universitaet Freiburg)
      • 09:00
        W/Z production at HERA 13m
        A search for events containing an isolated electron or muon and missing transverse momentum produced in e±p collisions is performed with the H1 and ZEUS detectors at HERA. The data were taken in the period 1994-2007 and correspond to an integrated luminosity of 0.98 fb-1. The total single W boson production cross section is measured as 1.06 ± 0.16 (stat.) ± 0.07 (sys.) pb, in agreement with a SM expectation of 1.26 ± 0.19 pb. The production of Z0 bosons in ep collisions at HERA has been searched for and the resulting di-jet invariant mass distribution is presented for the selected event topologies.
        Speaker: Amita Raval (DESY)
        Slides
      • 09:15
        Studies of polarized ep collisions and combined EW and QCD fits at HERA 13m
        Using the deep inelastic e+p and e-p neutral and charged current scattering cross sections, including data with polarised electron beams, a combined electroweak and QCD analysis is performed. The inclusive single differential cross section d(sigma)/d(Q^2) and the reduced double differential cross section sigma tilde(x,Q^2) are presented for the charged current process, e+/- p -> nu X, in interactions with longitudinally polarised lepton beams using the complete HERA-II data set. The inclusive single differential cross section d(sigma)/d(Q^2) and the reduced double differential cross section sigma tilde(x,Q^2) are presented for the neutral current process, e+/- p -> e+/- X, in interactions with longitudinally polarised lepton beams using the complete HERA-II data set.
        Speaker: Vladimir Chekelian (MPI fuer Physik)
        Slides
      • 09:30
        W and Z boson production and properties at the Tevatron 17m
        We present results of W and Z boson studies at the Tevatron including Drell-Yan cross sections measurement, W boson charge asymmetry, Z/gamma forward-backward asymmetry as well as transverse momentum distribution.
        Speaker: Terry Wyatt (University of Manchester)
        Slides
      • 09:50
        Measurement of W and Z boson production in pp at sqrt(s) = 7 TeV with the ATLAS detector 17m
        The first measurement of the production cross-sections for W and Z bosons in proton-proton interactions at sqrt(s) = 7 TeV are reported from the ATLAS experiment. Based on its excellent capability for reconstructing both high pT electrons and muons, the electron and the muon decay modes of the W/Z bosons are compared. First results for the ratio of W/Z production and of W+/W- production will also be described.
        Speaker: Laurent Serin (Laboratoire de l''Accelerateur Lineaire (LAL) (IN2P3) (LAL))
        Slides
      • 10:10
        W and Z boson production at CMS in pp collisions at sqrt(s)=7 TeV 17m
        The production of W and Z bosons has been observed in pp collisions at a center-of-mass energy of 7 TeV using data collected in the CMS experiment. W events were selected containing an isolated, energetic electron or muon. The presence of an energetic neutrino is demonstrated using the distribution of missing transverse energy (MET), which is calculated from calorimetric and tracking information in three ways. 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)=7 TeV, as well as preliminary distributions of kinematic variables.
        Speaker: Prof. Jeremiah Mans (University of Minnesota/CMS)
    • 09:00 10:30
      04 - Hadronic Structure, Parton Distributions, soft QCD, Spectroscopy Salle 251 ()

      Salle 251

      Convener: Volker Burkert (Jefferson Lab)
      • 09:00
        Extraction of Compton Form Factors from DVCS data 18m
        Generalized Parton Distributions (GPDs) allow to describe the structure of the nucleon in a very rich and unprecedented way: they contain the correlations between the (transverse) position and (longitudinal) momentum distributions of the partons in the nucleon, they allow to derive the orbital momentum contribution of partons to the nucleon's spin, they provide an access to the nucleon's (q-qbar) content, etc... GPDs can be accessed experimentally through the exclusive leptoproduction of a photon (``Deep Virtual Compton Scattering", DVCS) -and possibly of a meson-. In this presentation, we will present the result of our fitter code which aims at extracting, in a largely model-independent way, the GPD information (Compton Form Factors -CFF-) from experimental data. We will show the results of this code applied to the JLab and HERMES DVCS data. In particular, we have extracted some first important constraints on the Htilde CFF, from the HERMES and CLAS DVCS data obtained with a longitudinally polarized proton target. The kinematical dependence (xB,t) of these CFFs provides some new insights on nucleon structure.
        Speaker: Dr. Michel Guidal (CNRS/IPN Orsay)
        Slides
      • 09:20
        On chiral-odd Generalized Parton Distributions 8m
        The chiral-odd transversity generalized parton distributions of the nucleon can be accessed experimentally through the exclusive photoproduction process gamma + N -> pi + rho + N', in the kinematics where the meson pair has a large invariant mass and the final nucleon has a small transverse momentum, provided the vector meson is produced in a transversally polarized state. Estimated counting rates show that the experiment is feasible with real or quasi real photon beams expected at JLab@12 GeV and in the COMPASS experiment. (Phys Letters B688,154,2010) In addition, a consistent classification of the chiral-odd pion GPDs beyond the leading twist 2 is presented. Based on QCD equations of motion and on the invariance under rotation on the light-cone of any scattering amplitude involving such GPDs, we reduce the basis of these chiral-odd GPDs to a minimal set.
        Speaker: Samuel Wallon (LPT, Université Paris-Sud, CNRS, Orsay and UPMC Univ. Paris 06)
        Slides
      • 09:30
        The nucleon's transversity and the photon's distribution amplitude probed in lepton pair photoproduction 8m
        We describe a new way to access the chiral odd transversity parton distribution in the proton through the photoproduction of lepton pairs. The basic ingredient is the interference of the usual Bethe Heitler or Drell-Yan amplitudes with the amplitude of a process, where the photon couples to quarks through its chiral-odd distribution amplitude, which is normalized to the magnetic susceptibility of the QCD vacuum. A phenomenology of single and double spin observables emerges from the unusual features of this amplitude (Phys.Rev.Lett.103:072002,2009).
        Speaker: Lech Szymanowski (Soltan INS, Warsaw)
        Slides
      • 09:40
        Deeply Virtual Exclusive Reactions with CLAS 18m
        Deeply Virtual Exclusive Reactions with CLAS Deeply virtual exclusive reactions offer an unique opportunity to study the structure of the nucleon at the parton level as one varies both the size of the probe, i.e. the photon virtuality Q^2, and the momentum transfer to the nucleon t. Such processes can reveal much more information about the structure of the nucleon than either inclusive electroproduction (Q^2 only) or elastic form factors (t=-Q^2). A dedicated experiments to study Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP) has been carried out in Hall B at Jefferson Lab. DVCS helicity-dependent and helicity–independent cross sections, as well as beam spin asymmetry, and cross sections and asymmetries for the π0 and η exclusive electroproduction in a very wide kinematic range of Q^2, xB and t have been measured with CLAS. The preliminary data will be presented for the wide kinematic range in Q^2=1-4.5 GeV^2, xB=0.1-0.5 and t up to 2 GeV^2. We view the work presented in this report as leading into the program of the Jefferson Lab 12 GeV upgrade. The increased energy and luminosity will allow us to make the analysis at much higher Q^2 and xB and perform Rosenbluth L/T separations of the cross sections. Exclusive electroproduction of the rho+ meson on the proton at CLAS We will present our latest results on rho+ exclusive electroproduction on the proton measured with the CLAS detector of Jefferson Lab. We have measured for the first time ever for this process the longitudinal and transverse parts of the cross sections in the kinematic domain 0.15
        Speaker: Dr. Valery The CLAS Collaboration (Jefferson Lab)
        Slides
      • 10:00
        Deeply Virtual Compton Scattering off deuteron and twist three contributions 13m
        We study a deeply virtual Compton scattering off a spin-one particle, as the case for coherent scattering on a deuteron target. We discuss the role of twist three contributions for restoring the gauge invariance of the amplitude corresponding to this process. We consider both kinematical and dynamical sources of twist three generalized parton distributions. The role of the QCD equations of motion is discussed in detail. We derive a new kind of the Wandzura-Wilczek relations between the twist-2 and twist-3 generalized parton distributions.
        Speaker: Dr. Igor Anikin (Joint Inst. for Nuclear Research)
        Slides
      • 10:15
        Medium Modification of Vector Mesons 13m
        The theory of the strong interaction, Quantum Chromodynamics (QCD), has been remarkably successful in describing high-energy and short-distance-scale experiments involving quarks and gluons. However, applying QCD to low energy and large-distance scale experiments has been a major challenge. Chiral symmetry is one of the most fundamental symmetries in QCD and provides guiding principles to deal with strong interaction phenomena in the non-perturbative domain. Various QCD-inspired models predict a partial restoration of chiral symmetry in nuclear matter with modifications of the properties of hadrons from their free-space values. Measurable changes such as a shift in mass and/or a change of width are predicted at normal nuclear density. Photoproduction of vector mesons off nuclei were performed at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). The properties of the ρ, ω and φ mesons were investigated via their rare leptonic decay to e+e-. The latest results regarding medium modifications of the vector mesons in the nuclear medium will be discussed and a brief summary of the next round of experiments at different laboratories will be given.
        Speaker: Prof. Chaden Djalali (University of South Carolina)
        Slides
    • 09:00 10:30
      05 - Heavy Quarks Properties (experiment and theory) Salle 242 ()

      Salle 242

      Convener: Emi Kou (LAL/IN2P3)
      • 09:00
        Quarkonium production at the Tevatron and the LHC 15m
        In this talk, I will present recent progress on quarkonium production within NonRelativistic QCD. I will first give a brief introduction of the framework, and discuss the still open questions. I will emphasize the impact of the QCD corrections to several observables, including the pT spectrum and the polarization of J/ψ and Υ states produced in hadron collisions. After comparing up-to-date predictions with the Tevatron data, I will finally present some benchmark expectations for the production rate at the LHC.
        Speaker: Pierre Artoisenet (The Ohio State University)
        Slides
      • 09:15
        Double quarkonium production at the LHC 15m
        We study the production of two S-wave heavy quarkona at the LHC in the framework of nonrelativistic QCD. We consider the double quarkonium production of same flavour, J/ψ+J/ψ or Υ+Υ as well as that of different flavour, J/ψ+Υ. We calculate the short-distance coefficients in the colour-octet model completely for the first time. Our results for the differential cross section for the J/ψ+J/ψ or Υ+Υ production imply that the previous results carried out under the gluon fragmentation approximation greatly overestimated the cross section. This confirms that the gluon fragmentation approximation is valid only at large transverse momentum. Nevertheless we conclude that the colour-octet mechanism can be tested at the LHC in these channels. We also suggested the double quarkonium production of different flavour, J/ψ+Υ. We show that the tree-level and one-loop level contribution to this channel in the colour-octet model is much suppressed compared to that in the colour-octet model. Thus the J/ψ+Υ production at the LHC will provide probes of the colour-octet mechanisms with less backgrounds and without the colour-singlet contamination. If we can not observe the events at a expected level, it would imply that the current values of the colour-octet matrix elements are overestimated.
        Speaker: Chaehyun Yu (KIAS)
        Slides
      • 09:30
        Prompt J/psi and b -> J/psi X production in pp collisions at sqrt(s) = 7 TeV 15m
        Despite large experimental and theoretical efforts, the production rate and polarization of quarkonia states in hadronic collisions is not yet satisfactorily understood. With its first ~10 pb−1 of data, LHCb will be able to provide fresh measurements of the prompt and non-prompt J/ψ production cross sections, at the new center-of-mass energy of 7 TeV and in a unique range of rapidity (3 < y < 5) and transverse momentum (pT < 7GeV/c). The statistical separation between the prompt component and the contribution from b-hadron decays will be achieved using the distance between the pp collision point and J/ψ decay vertex. Preliminary measurements will be compared with predictions, and prospects for the extraction of the prompt J/ψ polarization, and prospects for the measurement of other quarkonia states will be discussed in the light of the first available signals.
        Speaker: Giovanni Passaleva (Istituto Nazionale di Fisica Nucleare (INFN) - Florence)
        Slides
      • 09:45
        Measurement of J/psi, Upsilon and b-hadron production in proton-proton collisions at sqrt(s) = 7 TeV with the CMS experiment 15m
        We present the first measurements of the J/ψ and Υ production cross sections in proton-proton collisions at 7 TeV, as measured by the CMS experiment using the dimuon decay channel. For the J/ψ we give the inclusive and the prompt differential cross sections, versus transverse momentum, as well as the beauty fraction, statistically separating the two contributions through a fit to the lifetime distribution, using the distance between the dimuon vertex and the interaction point. For the Υ, we present the 1S cross section and the (2S+3S)/1S cross-section ratio, both versus transverse momentum.
        Speaker: Nuno Leonardo (Purdue)
        Slides
      • 10:00
        Study of Jpsi production at central rapidity with the ALICE experiment at LHC. 15m
        In this Conference contribution, we summarize the status of the ongoing analysis on J/ψ production at central rapidity in pp collisions at sqrt(s)=7 TeV and show the first results. We also give perspectives on the first quarkonium measurements at central rapidity in Pb-Pb collisions which are scheduled by the end of this year.
        Speaker: Dr. Giuseppe Bruno (University and INFN, Bari, Italy)
        Slides
      • 10:15
        Initial-state-radiation production of Ds Mesons and high precision measurements of Ds1(2536) at Babar 15m
        A search for charmonium and other new states is performed in a study of exclusive initial-state-radiation production of Ds+Ds-, Ds*+Ds-, and Ds*+Ds*- events from electron-positron annihilations at a center-of-mass energy of 10.58 GeV. The data sample corresponds to an integrated luminosity of 525 fb-1 recorded by the BaBar experiment at the PEP-II storage ring. We also study the decay width and the mass of the Ds1(2536) meson with high precision via the decay channel Ds1(2536)->D+* K0s using 384 fb-1 of data recorded by the BABAR experiment.
        Speaker: Joseph Michael Izen (University of Texas at Dallas)
        Slides
    • 09:00 10:30
      08 - Heavy Ion Collisions and Soft Physics at Hadron Colliders Salle 253 ()

      Salle 253

      Convener: Raphael Granier De Cassagnac (Ecole Polytechnique, CNRS-IN2P3)
      • 09:00
        Jet reconstruction in heavy ion collisions 16m
        Jet algorithms cluster final state particles in high energy collisions with the aim of identifying "jets" that can be considered as proxies of the original hard partons, and therefore allow one to study their production mechanism and subsequent evolution. In heavy ion collisions, this task is severely complicated by the huge underlying event that accompanies the hard one: the particle content of jet is contaminated by a multitude of low-momentum particles, unrelated to the hard collision. This contamination must be understood and removed before the genuinely hard content of a jet can be studied. We will present a proposal for doing so using standard jet-algorithms (so as to facilitate the comparison with proton-proton results) and an entirely data-driven technique.
        Speaker: Matteo Cacciari (LPTHE Paris)
        Slides
      • 09:20
        Jet-medium interactions in heavy ion collisions 16m
        One of the most remarkable discoveries of the ongoing heavy ion physics program at RHIC is the experimental observation of the jet quenching. The STAR detector, with its extended angular coverage, has made possible novel studies of jet interactions with QCD matter using angular correlations. Di- and tri-hadron correlation studies have shown evidence of strong interactions between hard partons and the QCD matter, providing experimental constrains on medium properties, jet fragmentation and theoretical models of energy loss. Jet reconstruction, recently becoming available, can provide a more direct measurement of the initial parton energy, thereby further advancing our knowledge of jet-medium interactions. In this talk an overview of recent STAR results for jet quenching via triggered correlations will be presented along with the first measurements from jet reconstruction in Au+Au collisions.
        Speaker: Olga Evdokimov (University of Illinois at Chicago)
        Slides
      • 09:40
        Jets and Jet-like Correlations in Heavy Ion and p+p Collisions at PHENIX 16m
        Jets from heavy ion collisions provide a measurement of the medium-induced parton energy loss and the in-medium fragmentation properties, and therefore can significantly enhance our understanding of the energy loss mechanism and medium property. The medium modification effects are determined by comparing to a p+p baseline measurement. However the presence of high multiplicity backgrounds in heavy ion collisions inhibits the direct application of traditional jet reconstruction techniques. Instead angular correlations between the hadronic fragments of energetic partons can be used to understand the hot dense matter produced in relativistic heavy ion collisions. The yield and shape modifications of the away side peaks as function of transverse momentum compared to p+p has been interpreted as a medium response to parton energy loss. Direct photon--hadron correlations are another excellent channel to study jets from heavy ion collisions. Photons do not interact strongly with the medium and thus the photon approximately balances the momentum of the opposing jet, allowing the measurement of the effective modification to the fragmentation function through jet energy loss in the medium. We will present the latest jet measurements by PHENIX for p+p and heavy ion collisions.
        Speaker: Chris Pinkenburg (BNL)
        Slides
      • 10:00
        First glance at hard scattering phenomena with ALICE at LHC 12m
        In the first LHC 2009 and 2010 runs ALICE experiment collected about 10 nb-1 at √s=900 GeV and 10 μb-1 at √s=7 TeV of minimum bias p + p events. I will present a first look at the hard scattering phenomena exploring high-pT leading charged hadron correlations. An azimuthal and pseudorapidity correlations are analyzed in order to extract the mean transverse fragmentation momentum <jt> and intrinsic primordial parton momentum <kt>, massive hadron pairs production is used to study the NLO phenomena.</kt></jt>
        Speaker: Jan Rak (BNL)
        Slides
      • 10:15
        Phase diagram of hot QCD in an external magnetic field 12m
        The structure of the phase diagram for strong interactions becomes richer in the presence of a magnetic background, which enters as a new control parameter for the thermodynamics, and can exhibit new phases and interesting features. Motivated by the relevance of this physical setting for current and future high-energy heavy ion collision experiments and for the cosmological QCD transitions, we use the linear sigma model coupled to quarks and to Polyakov loops as an effective theory to investigate how the chiral and the deconfining transitions are affected, and present a general picture for the temperature-magnetic field phase diagram. We compute and discuss each contribution to the effective potential for the approximate order parameters, and uncover new phenomena such as the paramagnetically-induced breaking of Z(3).
        Speaker: Prof. Eduardo Fraga (Instituto de Fisica, Universidade Federal do Rio de Janeiro)
        Slides
    • 09:00 10:30
      12 - Beyond Quantum Field Theory Approaches (including String Theories) Salle 252A ()

      Salle 252A

      Convener: Martin Schnabl (Prague)
      • 09:00
        Scattering amplitudes in maximally supersymmetric Yang-Mills theory 18m
        I will review a recent progress in computing scattering amplitudes in maximally supersymmetric Yang-Mills theory. In addition to the conventional symmetry of the underlying Lagrangian, the scattering amplitudes in this theory exhibit a new, dual superconformal symmetry. This symmetry is powerful enough to completely determine the scattering amplitudes for arbitrary coupling in a suitably defined limit.
        Speaker: Prof. Gregory Korchemsky (CEA Saclay)
        Slides
      • 09:22
        Perturbative Quantum Gravity from Gauge Theory 18m
        In a previous paper we observed that (classical) tree-level gauge theory amplitudes can be rearranged to display a duality between color and kinematics. Once this is imposed, gravity amplitudes are obtained using two copies of gauge-theory diagram numerators. Here we suggest that this duality persists to all quantum loop orders and can thus be used to obtain multi-loop gravity amplitudes easily from gauge-theory ones. As a non-trivial test, we show that the three-loop four-point amplitude of N=4 super-Yang-Mills theory can be arranged into a form satisfying the duality, and by taking double copies of the diagram numerators we obtain the corresponding amplitude of N=8 supergravity. We also remark on a non-supersymmetric two-loop test based on pure Yang-Mills theory resulting in gravity coupled to an anti-symmetric tensor and dilaton.
        Speaker: Henrik Johansson (IPhT CEA Saclay)
        Slides
      • 09:44
        Monodromies and the structure of gauge and gravity amplitudes 18m
        We show that different color-ordered tree-level amplitudes in gauge theories satisfy monodromy relations. These relations imply the existence of minimal basis of amplitude and provide the numerator factors of the amplitude for a parametrisation of the tree-level amplitude using only cubic vertices. Applications to supergravity amplitudes follow straightforwardly through the KLT-relations. Through the cuts, these tree-level relations give rise to non-trivial identities at loop level. At higher loop this constrains the critical ultraviolet behaviour of the four-graviton amplitude in N=8 supergravity to all order in perturbation. We argue this implies that the four-graviton N=8 amplitudes has a seven-loop logarithmic divergence in four dimensions.
        Speaker: Pierre Vanhove (IPHT CEA/Saclay & IHES)
        Slides
      • 10:06
        Bounds on Anomalous Dimensions and OPE Coefficients from Crossing Symmetry in 4D CFTs. Applications to Conformal Technicolor and Unparticles. 18m
        A classic result of 4D CFT says that, in a unitary theory, a scalar operator of dimension d=1 is free. We will present results showing in which sense a scalar O of dimension d>1 but close to 1 is "nearly free". Namely, we analyze the OPE OxO of such a scalar with itself and show that 1) there must be a scalar of dimension 2+O(sqrt(d-1)) in this OPE; 2) in the d->1 limit, no scalars of dimension different from 2 can appear in this OPE. Our methods use the crossing symmetry constrant for the 4-point function <oooo>. They give numerical bounds on anomalous dimensions and OPE coefficients even as d-1 gets large. Apart from theoretical interest, such bounds have application to phenomenology (models of conformal EWSB and unparticles).</oooo>
        Speaker: Slava Rychkov (ENS & Jussieu)
        Slides
    • 10:30 11:00
      Coffee Break 30m
    • 11:00 12:30
      01 - Early Experience and Results from LHC Salle Maillot ()

      Salle Maillot

      Convener: Thomas Ruf (CERN)
      • 11:00
        Operation, calibration and performance of the CMS silicon tracker 15m
        The CMS tracker is the largest silicon detector ever built, covering an area close to 200 m2 and consisting of 15 148 silicon strip and 1440 silicon pixel modules. The use of tracker data in physics analysis requires fine-grained monitoring and calibration procedures. Results from timing studies, threshold optimization, calibration of gains and Lorentz angle determination are shown and the impact on resolution and dE/dx measurements is discussed. In order to achieve an optimal track-parameter resolution, the position and orientation of its modules need to be determined with a precision of few micrometers and an accurate representation of the distribution of material in the tracker is needed. Results of the alignment of the full tracker are presented, based on the analysis of several million reconstructed tracks recorded during the commissioning of the CMS experiment with cosmic rays and the first proton-proton collisions. They have been validated by several data-driven studies and compared with predictions obtained from a detailed detector simulation. Reconstructed photon conversions and nuclear interactions have been used for a first estimate of the tracker material.
        Speaker: Steven Lowette (UCSB)
        Slides
        Video
      • 11:18
        Commissioning and Performance of the ATLAS Inner Detector with proton-proton Collisions at the LHC 15m
        ATLAS is a multipurpose experiment which records the products of the LHC collisions. To reconstruct trajectories of charged particles produced in these collisions, the experiment is equipped with large-scale tracking systems built of silicon planar sensors (pixel and strip-based), as well as a drift‐tube based detector system. This talk will cover the first experience gained with these tracking systems, such as the commissioning and first operational experience, including monitoring and calibration procedures. The talk will further address the alignment procedures and the results obtained. Finally, the performance of the tracking systems with the LHC in collison mode will be presented and compared with the expected parameters and with the Monte Carlo simulations, also covering their particle identification capabilities.
        Speaker: Dr. Antonio Limosani (University of Melbourne)
        Slides
        Video
      • 11:36
        Performance of the Tracking System at the LHCb Experiment 15m
        The LHCb detector is a forward spectrometer. Its tracking system consists of silicon strip detectors and straw tube drift chambers. The LHCb experiment is dedicated to the reconstruction of B decays into many particle final states. For a high B reconstruction efficiency a high efficient track reconstruction is crucial. We will report on the performance of the individual tracking subdetectors in terms of hit resolution and detector efficiencies as well as on the overall track reconstruction performance.
        Speaker: Silvia Borghi (University of Glasgow)
        Slides
        Video
      • 11:54
        Performance of Track and Vertex Reconstruction and b-Tagging Studies with ATLAS in pp Collisions at √s = 7 TeV 15m
        First 7 TeV proton-proton collisions produced by the Large Hadron Collider at CERN have been recorded by the ATLAS experiments in 2010. The ability to accurately and efficiently reconstruct the trajectories of charged particles produced in these collisions is a critical component in the measurements that will be presented at this conference. This talk will present results on the performance of tracking and vertex-reconstruction using the ATLAS tracking systems. Various methods are employed by the two experiments for determining the efficiency of track reconstruction using the first data collected by the detectors. Furthermore, the methods to control the track momentum scale and related systematic uncertainties will be discussed. Finally, the reconstruction of known particle decays is presented as important tool to understand the tracking and vertexing performance, as well as the particle identification capabilities. The identification of b-quark jets is an important tool for the physics programs of the ATLAS experiment. So-called b-tagging algorithms take advantage of either the decay to a soft lepton or a displaced vertex caused by the long-lived decay of a b hadron via the weak force. As a result key ingredients to b-tagging algorithms are the precise trajectory measurement of charged particle tracks and detection of low pT leptons. The distributions of the corresponding observables - track impact parameters, secondary vertices and lepton momenta - were measured in pp collisions at √s=7 TeV, and compared to the predictions from Monte Carlo simulation. First results on efficiencies and mis-identification rates are shown. The calibration strategies that will be used for early data and initial studies that will lead to a fully data-driven calibration for the b-tagging algorithms are also presented.
        Speaker: Johanna Fleckner (CERN / University of Mainz)
        Slides
        Video
      • 12:12
        Performance of Track and Vertex Reconstruction and B-Tagging Studies with CMS in pp Collisions at √s = 7 TeV 15m
        First 7 TeV proton-proton collisions produced by the Large Hadron Collider at CERN have been recorded by the CMS experiment in 2010. The ability to accurately and efficiently reconstruct the trajectories of charged particles produced in these collisions is a critical component for most measurements at the LHC. We present several methods for determining the efficiency and measuring the resolution and the momentum scale of track reconstruction in CMS using the first data collected by the detector. The trajectories of charged particles are the key elements for the reconstruction of the primary interaction vertex and for the identification of jets containing the products of a B-hadron weak decay. The distributions of the key observables, such as track impact parameters and vertex properties, are compared with the prediction of Monte Carlo simulation. Finally the performance of vertex reconstruction and B identification algorithms as directly derived from data are shown.
        Speaker: Boris Mangano (UCSD)
        Slides
        Video
    • 11:00 12:30
      02 - The Standard Model and Electroweak Symmetry Breaking Salle 252B ()

      Salle 252B

      Convener: Maarten Boonekamp (DAPNIA)
      • 11:00
        Top-quark production at the Tevatron and LHC 20m
        We review recent theoretical progress concerning top-quark pair production at the Tevatron and LHC. In particular we present updated theoretical predictions taken into account the newest pdf's. Furthermore we comment on the possibility of a direct measurement of the running top-quark mass.
        Speaker: Peter Uwer (Humboldt-Universität zu Berlin)
        Slides
      • 11:22
        Studies of single top quark production at the Tevatron 20m
        Using events containing an isolated lepton and missing transverse energy, together with jets originating from the fragmentation of b quarks, we measure the cross section of single top quark production. Measurements of the t-channel and s-channel, matrix element Vtb and search for Flavor Changing Neutral Currents are also performed.
        Speaker: Breese Quinn (University of Mississippi)
        Slides
      • 11:45
        Measurement of the top quark pairs production cross sections and differential distributions of top quarks at the Tevatron 20m
        We present precision measurements of the top quark pair production cross sections in ppbar collisions at a center of mass energy of sqrt(s)=1.96 TeV in up to 5 fb-1 of data as well as results of study of kinematics distributions of top quark pairs produced.
        Speaker: Fabrizio Margaroli (Purdue)
        Slides
      • 12:08
        Top quark pair and single top production at Tevatron and LHC energies 20m
        I present the latest theoretical developments in the calculation of the cross section for top-antitop pair production and single top quark production via all main partonic channels. Higher-order corrections from resummation of soft gluons are added through NNLL accuracy. Detailed numerical results are presented for the cross section and transverse momentum distributions at the Tevatron and LHC colliders.
        Speaker: Prof. Nikolaos Kidonakis (Kennesaw State University)
        Slides
    • 11:00 12:30
      04 - Hadronic Structure, Parton Distributions, soft QCD, Spectroscopy Salle 251 ()

      Salle 251

      Convener: Barbara Pasquini (University of Pavia)
      • 11:00
        Hard exclusive processes in the backward region 13m
        We discuss the potentialities offered by the study of backward exclusive processes in the scaling regime, i.e. involving a large Q2 photon and a baryonic exchange in the t-channel. We introduce the concept of Transition Distribution Amplitudes (TDAs) containing unique information on the hadron structure, then discuss how they enter the description of processes such as backward electroproduction of a pion, antiproton-proton annihilations into a dilepton + meson as well as into J/Psi + meson. We discuss first estimates of cross sections that are being measured at JLAB along with predictions for processes for Panda at GSI-FAIR. Finally we present outlooks for their theoretical studies based on approaches such as the pion cloud model.
        Speaker: Dr. Jean-Philippe Lansberg (Ecole polytechnique)
        Slides
      • 11:15
        Spin structure of the proton and Transverse Momentum Dependent distributions 18m
        The structure of the proton is described from the point of view of transverse momentum dependent distributions of partons. Complete set of functions describing the structure of the proton at leading twist is defined. TMDs can be studied experimentally in polarised inclusive processes such as Semi Inclusive Deep Inelastic Scattering.Factorization of Semi Inclusive Deep Inelastic Scattering and the properties of the distribution and fragmentation functions with presence of so-called gauge links will be discussed.
        Speaker: Alexei Prokudin (University of Turin)
        Slides
      • 11:35
        Transverse momentum dependent splitting functions and parton distributions. 13m
        This talk gives an introduction to transverse momentum dependent (unintegrated) parton distributions and presents the results of a recent study of quark splitting functions defined at fixed longitudinal and transverse momenta. We discuss the treatment of endpoint divergences, emphasizing the physical picture that underlies the need for infrared subtraction factors in the operator matrix elements that appear in the factorization formulas. We present results of a recent calculation for gluon-to-quark splitting kernel at fixed transverse momentum, and show that this kernel naturally emerges from renormalization of ultraviolet divergences in the operator matrix elements. We discuss prospects for phenomenological applications of the unintegrated formulation of QCD factorization.
        Speaker: Francesco Hautmann (Institute of Theoretical Physics)
        Slides
      • 11:50
        DVCS and TMDs Studies at HERMES 18m
        Recent Results on Deeply Virtual Compton Scattering at HERMES Deeply Virtual Compton Scattering is an elegant tool to investigate the angular momenta of partons inside the nucleon. Using longitudinally polarized electron and positron beams, HERMES has studied this process using various gaseous targets, in either unpolarized or longitudinal as well as transverse polarization states. This variety of experimental setups enable the extraction of a wealth of asymmetry amplitudes, which in turn are related to Generalized Parton Distributions (GPDs). This presentation will focus on the results obtained from a hydrogen and a deuterium target. In summary, the leading-twist asymmetry amplitudes are sizeable, while the suppressed higher twist contributions are compatible with zero. HERMES measurements of azimuthal asymmetries related to transverse-momentum dependent quark distributions The structure of the nucleon can be parametrised in terms of eight leading-twist quark distribution functions when including the transverse momentum of quarks in the description. They embody the correlations between the spin of the nucleon, the spin of the quarks and their longitudinal and transverse momentum. Only two of them, the momentum distribution f1q and the helicity distribution g1q can be measured in inclusive deep-inelastic lepton-nucleon scattering, all others can only be accessed in semi-inclusive measurements where in addition to the scattered lepton also a leading hadron is detected. Examples for such transverse-momentum dependent distribution functions are the 'transversity' distribution, the 'Sivers' and the 'Boer-Mulders' function. Each of these distributions causes distinctive signatures in the hadron’s azimuthal angular distribution around the direction of the exchanged virtual photon. The HERMES experiment at HERA has performed such measurements with polarized lepton beams of both helicities and unpolarized as well as longitudinally and transversely polarised targets and has determined the amplitudes of the azimuthal modulations for all leading-twist and several higher-twist contributions to the cross section. The results of these measurements will be reported.
        Speaker: Prof. Klaus The HERMES Collaboration (University of Erlangen)
        Slides
      • 12:10
        DVCS, TMDs and Spin Physics at COMPASS 18m
        Recent results on the nucleon spin structure from COMPASS COMPASS is a multi-purpose fixed target experiment at the CERN Super Proton Synchrotron, dedicated to the study of the spin and the structure of the nucleon. From 2002 to 2011, high statistics data for polarized inclusive and semi-inclusive deep inelastic scattering were collected using 160 GeV/c polarized muons on polarized deuteron and proton targets. The data are used to derive the gluon contribution to the nucleon spin, and to determine the up, down and strange quark and anti-quark polarized distributions. They also constrain the g1 longitudinal spin structure function, and thus the Björken sum rule, with greater accuracy. The implications of these results to our present understanding of the nucleon spin puzzle will be discussed. The COMPASS plans for the future will be presented. Prospects for a DVCS measurement at COMPASS The high energy polarised muon beam available at CERN with the option of using positive or negative muons with opposite polarisation gives COMPASS an excellent possibility to study generalised parton distributions via deeply virtual Compton scattering. In a first step we propose to use an unpolarised proton target to study the slope of the momentum transfer distribution as a function of xbj. Furthermore, the beam charge and spin difference will be measured over a wide kinematical range to determine the Compton form factor related fo the GPD H. As a second step we consider to use a transversely polarised proton target to collect data to constrain the GPD E. In preparation of the future measurements two DVCS test runs were performed in 2008 and 2009. Measurements of TMDs at COMPASS COMPASS is a fixed target experiment at CERN SPS, dedicated to the study of the nucleon spin structure with muon probe and on a variety of issues in the hadron spectroscopy sector. The transverse spin structure of the nucleon is investigated by measuring semi-inclusive deep inelastic scattering of a 160 GeV/c longitudinally polarized muon beam on transversely polarized targets. A review of new and old COMPASS results on transverse spin effects will be given i.e. the measurement of the Collins and Sivers effects, the two hadron asymmetries and the lambda baryons polarisation, both on a deuteron and on a proton target. Transverse momentum effects, like the Cahn and the Boer-Mulders effects were measured on an un-polarized deuteron target, and will also be presented. This year COMPASS is taking data on a transversely polarized proton target, to increase the precision of the measurements done in so far. But there are many other plans for the near future of COMPASS: successful test-beams were done to study the feasibility of both a polarized Drell-Yann measurement and a campaign dedicated to the study of the generalized parton distributions (GPD).
        Speaker: Dr. Fabienne The COMPASS Collaboration (CEA Saclay)
        Slides
    • 11:00 12:30
      05 - Heavy Quarks Properties (experiment and theory) Salle 242 ()

      Salle 242

      Convener: Changzheng YUAN (IHEP, Beijing)
      • 11:00
        Three-loop heavy quark potential 15m
        The three-loop corrections to the static potential between a quark and its anti-quark are considered. It constitutes a building block for a number of physical observables connected to heavy quarks. We describe the evaluation of the occurring integrals and discuss the phenomenological implications.
        Speaker: Prof. Matthias Steinhauser (KIT)
        Slides
      • 11:15
        Recent results of charmonium transitions at BESIII 15m
        We present the measurements of charmonium P-wave spin-singlet state h_c made with 106M ψ' events collected by BESIII at BEPCII. Clear signals are observed for ψ'->π0 h_c with and without the subsequent radiative decay h_c->γ η_c. First measurements of the absolute branching ratios Br(ψ'->π0 h_c) = (8.4 ± 1.3 ± 1.0)*10-4 and Br(h_c->γ η_c) = (54.3 ± 6.7 ± 5.2)% are also presented. A statistics-limited determination of the previously unmeasured h_c width leads to an upper limit Γ(h_c)<1.44 MeV (90% confidence). Measurements of M(h_c) = 3525.40 ± 0.13 ± 0.18 MeV/c² and the branching ratios are consistent with previous results. Also the observation of two-photon transition of ψ' to J/ψ based on the same data sample is reported. The measurement of the branching fraction is explicitly determined as Br(ψ'->γ γ J/ψ) = (1.02 ± 0.05(stat.) + 0.19 - 0.20(syst.))*10-3 with combination of the studies of two different J/ψ decay channels: J/ψ->e+e- and J/ψ->µ+µ-.
        Speaker: LI Gang (IHEP)
        Slides
      • 11:30
        Recent results of charmonium radiative decay from BESIII 15m
        With the high luminosity of electron-positron storage ring at BEPCII and excellent performance of the BESIII spectrometer, BESIII accumulated about 100 million ψ(2S) data. With the help of these high statistics and high quality data, the radiative decays of ψ(2S) into light meson P(P = π0, η, η'), and χcJ radiative decays to vector meson V (V = ρ, ω, φ) , together with χcJ decays into pseudoscalar pairs PP (P = π0, η) are studied at BESIII. The progress of these analyses will be reported in the conference.
        Speaker: Ronggang Ping (IHEP)
        Slides
      • 11:45
        Measurement psi(3770) resonance parameters with KEDR detector at VEPP-4M 15m
        We present a measurement of the mass, total width and leptonic width of the ψ(3770) meson. Results were obtained using data collected at the ψ(3770) resonance with the KEDR detector at the electron-positron accelerator complex VEPP-4M. The commonly used fitting procedure does not contain interference ψ(3770) resonance and non-resonant DDbar cross section. In our analysis we used a description of the ψ(3770) resonance shape including interference.
        Speaker: Korneliy Todyshev (BINP)
        Slides
      • 12:00
        Recent Quarkonium Results from BaBar 15m
        We present recent results on quarkonium states from the Babar experiment. We have observed the Y(^3 1 D_J) state of bottomonium in the reaction Y(3S)->γ γ Y(^3 1D_J), γ(^3 1 D_J)->π π Y(1S) with a significance of 6.2 standard deviations. We present a study of the decay Y(1S)->D+* + X produced in the decay Y(2S)->π+ π- Y(1S) using a sample of 98.6 million Y(2S) events. We measure the Y(1S)=>D+* + X branching fraction and the momentum distribution of the D* in the Y(1S) rest-frame. We find evidence for an excess of D* production over the expected rate from the virtual photon annihilation process Y(1S)->γ*->cbar c->D+* X. We also present a search for the spin singlet h_b partner of the χb(1P) triplet, the h_b(1P) state of bottomonium in the transition Y(1S)->π0 h_b and Y(3s)->π+ π- h_b using a sample of 122 million Y(3S) events.
        Speaker: Bryan Fulsom (SLAC National Accelerator Laboratory)
      • 12:15
        Perspectives for quarkonium production at the LHC 15m
        I will discuss the impact of QCD corrections (up to alpha_s^5) to quarkonium production at high energies and the introduction of new observables meant to better discriminate between the different mechanisms at work in quarkonium production at the LHC.
        Speaker: Dr. Jean-Philippe Lansberg (Ecole polytechnique)
        Slides
    • 11:00 12:30
      08 - Heavy Ion Collisions and Soft Physics at Hadron Colliders Salle 253 ()

      Salle 253

      Convener: Javier Albacete (IPhT CEA Saclay)
      • 11:00
        Heavy quarkonia production at STAR 16m
        According to lattice QCD calculation, the suppression pattern of quarkonia states is expected to provide insight into thermodynamic properties of hot and dense matter, Quark-Gluon Plasma (QGP), predicted to be created in relativistic heavy ions collisions at RHIC energies. The suppression in this calculation is caused by screening of the binding potential between quark and antiquark in QGP. To understand the suppression of heavy quark hadron production in heavy-ion collisions a systematic measurement is required in p+p, d+Au and Au+Au collisions. For J/ψ, the data from p+p collisions may allow us to understand the basic production mechanisms, such as due to direct production, parton fragmentation and feed down from higher states while the data from the p+A collision would provide insights into contributions from cold nuclear matter effects. In this talk we will report results on heavy quarkonia production via di-electron decay channel in mid-rapidity in p+p, d+Au, Cu+Cu and Au+Au collisions at sqrt(sNN)=200 GeV in STAR. Special emphasis would be given to J/ψ measurements at high pT to understand the basic processes of quarkonium production and to compare the measurements with several model calculations of the J/ψ nuclear modification factor. Measurements of Upsilon production in p+p, d+Au and Au+Au collisions will be also reported. Presented results will be compared with theoretical models for quarkonia production.
        Speaker: Daniel Kikola (Lawrence Berkeley Nat. Lab./Warsaw Univ. of Technology)
        Slides
      • 11:20
        Quarkonia measurements with the PHENIX detector 16m
        Over the last ten years the PHENIX experiment has continued to increase the amount of recorded and analyzed data available for p+p, d+Au and A+A colliding species at various energies. These data have allowed us to analyze J/ψ mesons in all three collision types which contributes to the understanding of J/ψ formation, suppression in cold nuclear matter and anomolous suppression in heavy ion collisions. In particular the recent d+Au J/ψ results have shown that it is very difficult to match the forward rapidity data with a shadowing model and constant break up cross section. In addition PHENIX has measured Ψ' and X_c cross sections in p+p collisions at 200 GeV and their feed-down into the J/ψ. Recently PHENIX has also measured the upsilon in p+p and d+Au collisions as well as setting an upper limit for the upsilons suppression in Au+Au collisions. These new measurements enrich the quarkonia story and will be discussed in context of their broader impact on the field. In addition to current measurements PHENIX is entering a period of upgrades where new capabilities are going to come available. In particular a new FVTX detector scheduled to be installed by the 2012 RHIC run promises to add the Ψ' in the di-muon channel and the forward calorimeter promises to help with the acceptance of the X_c. The SVTX detector will allow the unambiguous identification of open charm in the central arms of the detector which will benefit the closed charm measurements greatly.
        Speaker: Alex Linden-Levy (LLNL)
        Slides
      • 11:40
        Heavy flavour measurements with ALICE at the LHC 16m
        ALICE is the LHC experiment dedicated to the study of heavy-ion collisions. The main purpose of ALICE is to investigate the properties of a state of deconfined nuclear matter, the Quark Gluon Plasma. Heavy flavour measurements will play a crucial role in this investigation. The physics programme of ALICE has started by studying proton-proton collisions at unprecedented high energies. We will present the first results on open heavy flavour and quarkonia in proton-proton collisions at sqrt(s)=7 TeV measured by the ALICE experiment at both mid- and forward-rapidities. We will conclude with the prospects for heavy flavour and quarkonium measurements in both proton-proton and nucleus-nucleus collisions.
        Speaker: Dr. Javier Castillo Castellanos (Service de Physique Nucleaire (SPhN))
        Slides
      • 12:00
        Identified particle production in inelastic pp events with the ATLAS detector 12m
        Studies of the long-lived resonances Ks and Lambda, reconstructed in inelastic collisions at 900 GeV and 7 TeV using a minimum bias trigger, have been performed using the ATLAS inner tracking detector. The spectra for these resonances are measured as a function of their transverse momentum and rapidity, and compared with Monte Carlo models. The ratio of anti-Lambda to Lambda production is evaluated, providing further tests of Monte Carlo models. The results are corrected for all detector effects, to simplify comparisons to models and other experiments.
        Speaker: Leonid Gladilin (Moscow State University)
        Slides
      • 12:15
        Inclusive production of hyperons, as well as of pions, charged kaons, protons, anti-protons and neutrons in p+p collisions at 158 GeV/c beam momentum 12m
        New data on the production of hyperons, as well as of pions, charged kaons, protons, anti-protons, neutrons in p+p interactions are presented. The data come from a sample of 8.2 million inelastic events obtained with the NA49 detector at the CERN SPS at 158 GeV/c beam momentum. The high statistics data sample allows the extraction of detailed differential distributions as a function of x_f ,y and p_T. The results are compared with published data and models. Moreover, the measurements provide an important reference for studying effects of cold nuclear matter in proton-nucleus and hot dense matter in nucleus-nucleus collisisons.
        Speaker: Dr. Tome Anticic (Rudjer Boskovic Institute)
        Slides
    • 11:00 12:30
      12 - Beyond Quantum Field Theory Approaches (including String Theories) Salle 252A ()

      Salle 252A

      Convener: Kostas Skenderis (Amsterdam)
      • 11:00
        SUSY Breaking in the Klebanov-Strassler Background by Anti-D3 Branes 18m
        Constructing models of meta-stable vacua in supersymmetric theories is a crucial task for string phenomenology. It has been conjectured that anti-D3 branes in the Klebanov-Strassler background indeed produce such a supersymmetry breaking scenario. In this talk I will outline the results of a supergravity calculation which represents the backreaction of such anti-D3 branes and discuss the implications for finding meta-stable vacua from warped deformed conifolds.
        Speaker: Dr. Nick Halmagyi (CEA)
        Slides
      • 11:22
        Superstring Cosmology 18m
        In a string theory framework, one may unambiguously compute the free-energy density including the vacuum energy, in backgrounds with spontaneously broken supersymmetry. For certain classes of models, the resulting backreaction induces a cosmological evolution which mimics a radiation dominated expansion. The supersymmetry breaking scale is attracted to the temperature scaleand the internal moduli may be stabilized at points of enhanced symmetry. Finally the expansion may go through several higher dimensional phases, before the final attraction to a four dimensional evolution.
        Speaker: John Estes (ENS)
        Slides
      • 11:44
        Supersymmetry breaking branes and de Sitter vacua in generalised geometry 18m
        We discuss supersymmetry breaking compactifications in type IIA and we propose a new treatment of non-supersymmetric sources: for space-time filling supersymmetric branes, the energy density is minimized by a pullback of a special form given by a pure spinor. We propose to extremise the combined bulk-brane energy density by replacing the DBI action by a pullback of a polyform from the bulk, which is no longer pure.
        Speaker: Prof. Michela Petrini (CNRS/LPTHE)
        Slides
      • 12:06
        Loop quantum gravity and the early universe 18m
        Loop quantum gravity is, together with string theory, one on the major candidate approach to quantize gravity. It provides a framework which allows for a non-perturbative and background-independant canonical quantization of general relativity. In this talk, I will briefly go through the basic conceptual groundings of the theory and switch to the latests developments associated with its implementation in the cosmological context. I will show that the Big Bang is replaced by a Big Bounce (therefore solving the initial singularity problem) and that inflation unavoidably occurs. Furthermore, the primordial tensor power spectrum should exhibit some characteristic features that could lead to experimental tests of this "Planck-scale" physics.
        Speaker: Dr. Aurelien Barrau (LPSC Laboratoire de Physique Subatomique et de Cosmologie (LPSC))
        Slides
    • 12:30 14:00
      Lunch Break 1h 30m

      Lunches not provided.

    • 14:00 15:45
      01 - Early Experience and Results from LHC Salle Maillot ()

      Salle Maillot

      Convener: Guenther Dissertori (Institut fur Teilchenphysik)
      • 14:00
        Particle ID in LHCb 15m
        Particle identification (PID) is a fundamental requirement for LHCb and is provided by CALO, MUON and RICH sub-detectors. The Calorimeters provide identification of electrons, photons and hadrons in addition to the measurement of their energies and positions. As well as being part of the LHCb trigger, the MUON system provides identification of muons to a very high level of purity, essential for many CP-sensitive measurements that have J/Psi's in their final states. Hadron identification, in particular the ability to distinguish kaons and pions, is crucial to many LHCB analyses, particularly where the final states of interest are purely hadronic. The LHCb RICH system provides this, covering a momentum range between 1 and 100 GeV/c. To maintain the integrity of the LHCb physics performance, it is essential to measure and monitor the particle identification efficiency and misidentification fraction over time. This can be done by using specific decays, such as Kshorts, Phi's, Lambdas, J/psi's and D*'s, for which pure samples can be isolated using only kinematic quantities, due to their unique decay topologies. This allows for clean samples of known particle types to be selected, which can then be used to calibrate and monitor the PID performance from data. The procedures for performing this will be presented, together with preliminary results from the 2009 and 2010 LHC runs.
        Speaker: Andrew Powell (University of Oxford)
        Slides
        Video
      • 14:20
        Commissioning and Performance of the CMS Calorimeter Systems with proton-proton Collisions at the LHC 15m
        We present results on the commissioning and performance of the CMS electromagnetic and hadron calorimeters in pp collisions at a centre of mass energy of 7 TeV at the LHC. The first LHC beams have been used to finalize the commissioning of the readouts and triggers. The calibrations and synchronisations of the calorimeters using cosmic muons, beam splash events (where the LHC beam is targeted on upstream collimators), and collision data including reconstructed physics objects are presented. The quality of the offline data reconstruction, from low level quantities to showers, has been investigated and optimised using known physics processes. In-situ data and thorough data/MC comparisons have been used to measure and tune the detector performance. First performance results are given.
        Speaker: Philippe Gras (DAPNIA)
        Slides
        Video
      • 14:40
        Commissioning and Performance of the ATLAS Calorimeter Systems with proton-proton Collisions at the LHC 15m
        The commissioning, operation and general performance of the electromagnetic and hadronic calorimeters of ATLAS will be presented, as achieved using random triggers, calibration data, cosmic muons, and LHC proton-proton collisions. Methods will be presented for verifying the precision of inter-channel synchronization and calibration, and their improvement with in-situ data.
        Speaker: Pascal Pralavorio (Faculte des Sciences de Luminy-Centre de Physique des Particules)
        Slides
        Video
      • 15:00
        Electron and Photon Performance and Electron pT Spectrum Measurement with ATLAS in pp Collisions at √s = 7 TeV 15m
        The understanding of the reconstruction of electrons in the ATLAS experiment at LHC is one of the key issues for the 2010 run at a center of mass energy of 7 TeV. Two aspects are of interest: the energy calibration and the reconstruction efficiency. The energy measurement of electrons is based on the electromagnetic calorimeter over most of the relevant energy range (5 GeV to a few TeV). The electromagnetic calorimeter clusters are formed from electronically calibrated calorimeter cells and are corrected for local position and energy variations. A refined calibration procedure, developed and validated over years of test-beam strives to identify all sources of energy losses upstream of the outside the cluster and corrects for them one by one (using Monte Carlo). The present study is aiming at a first validation of this calibration strategy on prompt electrons from known physics processes. The electron reconstruction efficiency can be measured with data using a tag-and-probe approach with J/psi->ee and Z->ee decays. An initial measurement will be shown with the first pb-1 and compared to MC. The talk also presents a first measurement of the inclusive electron transverse momentum (pT) spectrum in proton proton collisions at a center of mass energy of 7 TeV using a data sample of a few pb-1.
        Speaker: Scott Snyder (Brookhaven National Laboratory (BNL))
        Slides
        Video
      • 15:20
        Electron and Photon reconstruction and identification with the CMS detector in pp collisions at √s = 7 TeV 15m
        The performance of electron and photon reconstruction and identification has been studied at √s = 7 TeV. Reconstruction and identification variables as well as isolation and photon conversion rejection variables, in the case of electrons, have been compared between data and Monte Carlo for signal and background. Electron and photon identification efficiency, electron fake rate and photon purity have been determined and compared with Monte Carlo predictions. For electrons the momentum resolution as well as charge identification have also been studied. Level 1 Trigger and High Level Trigger efficiencies have been measured.
        Speaker: Salerno Roberto (LLR-Ecole Polytechnique)
        Slides
        Video
    • 14:00 15:45
      02 - The Standard Model and Electroweak Symmetry Breaking Salle 252B ()

      Salle 252B

      Convener: Dmitri Denisov (Fermi National Accelerator Laboratory (FNAL))
      • 14:00
        V+jet production at the LHC: Electroweak radiative corrections 20m
        The investigation of weak bosons (W^+/W^-,Z) produced with associated hard QCD jets will be of great phenomenological interest at the LHC, since such processes constitute an important background to a large variety of BSM-physics signatures. At the same time - owing to their large production cross sections and the clear decay signatures of the vector bosons - they can be used to monitor and calibrate the luminosity of the collider, constrain the PDFs, or for detector calibration. To match the excellent experimental accuracy that is expected at the LHC, we have worked out a theoretical NLO analysis of V+jet production at hadron colliders. The focus of this talk will be on new results on the electroweak corrections to Z+jet production at the LHC. We present some details of the calculation, and discuss the phenomenological implications of our results.
        Speaker: Dr. Tobias Kasprzik (KIT, Karlsruhe)
        Slides
      • 14:22
        WZ cross section and W mass measurement at DZero 18m
        We present results of the WZ production cross section measurement and W mass measurement in electron channel with the DZero detector at sqrt(s) = 1.96 TeV.
        Speaker: Joseph Haley (FNAL)
        Slides
      • 14:42
        Studies of WW and WZ production at CDF 18m
        We present studies of the WW and WZ production cross sections with CDF II detector from p-pbar collisions at sqrt(s) = 1.96 TeV in different final states.
        Speaker: viviana cavaliere (INFN Pisa)
        Slides
      • 15:02
        Di-boson production and limits on triple gauge boson couplings at the Tevatron 20m
        Studies of di-boson production including production of ZZ and Zg production and updated stringent limits on triple gauge boson couplings will be presented. The ZZ sample is used also to search for gg → H → ZZ to constrain fourth generation fermion models.
        Speaker: Prof. Thomas Phillips (Duke University)
        Slides
      • 15:25
        Study of multi-lepton events at HERA 18m
        Events with at least two high transverse momentum leptons (electrons or muons) are studied using the H1 and ZEUS detectors at HERA. Seven di- and tri-lepton events are observed in e+p collision data with a scalar sum of the lepton transverse momenta above 100 GeV, while 1.94 +- 0.17 events are expected. Such events are not observed in e-p collisions for which 1.19 +- 0.12 are predicted. A search for events containing two high-transverse-momentum tau leptons has been performed and observed results will be presented.
        Speaker: Dr. David South (DESY)
        Slides
    • 14:00 15:45
      04 - Hadronic Structure, Parton Distributions, soft QCD, Spectroscopy Salle 251 ()

      Salle 251

      Convener: Enrico Tassi (Dipartimento di Fisica-Univ. degli Studi della Calabria)
      • 14:00
        Two-photon exchange and elastic scattering of positrons/electrons on the proton 13m
        We report the experiment on a precise comparison of (e+ p) and (e- p) scattering cross sections, which gives a direct experimental evidence for the two-photon exchange (TPE) contribution in this reaction. Such data are in demand now, because they, most likely, may explain the dramatic disagreement of proton electromagnetic form factors measurements in the polarization transfer (PT) experiments at Jefferson Lab with previous unpolarized measurements using a Rosenbluth separation (RS) technique. Common practice of the analysis of RS experiments was in approximate taking into account of TPE contribution, believing this contribution to be small. Currently there are no accurate calculations of the TPE contribution, what is related to difficulties in accounting of the intermediate states of proton. But recent calculations, which takes particular account of proton structure, shows importance of TPE contribution for RS analysis. As far as the experimental situation, only old (in 1960th) measurements exist, where the TPE contribution were found with low precision and limited kinematics coverage. Reported experiment was performed recently at VEPP-3 storage ring at the energy of positron/electron beams 1.6 GeV and three regions of electron/positron scattering angle - around 10, 18 and 64 degrees. The smallest angle region was used for luminosity monitoring. Electron and positron beams were replaced each other regularly, one cycle with two beams required 1.5 hours. Internal hydrogen gas target had a thickness 5*10^14 at/cm2. Experiment duration was 1500 hours with a mean luminosity of 5*10^31 1/(s cm2). The preliminary results on (e+ p)/(e- p) cross sections ratio will be presented.
        Speaker: Dmitri Nikolenko (Budker Institute for Nuclear Physics)
        Slides
      • 14:15
        Parton Distributions at the dawn of the LHC 18m
        I review the current status of knowledge of the parton distributions (PDF) of the nucleon, with particular emphasis on recent progress on the determination of PDF uncertainties and on theoretical and phenomneological issues which limit the current PDF accuracy. I then discuss the implications of PDF uncertainties on LHC processes, with specific references to standard candles and Higgs production.
        Speaker: Prof. Stefano Forte (Milan University)
        Slides
      • 14:35
        Dynamical Parton Distributions and Weak Gauge and Higgs Boson Production at Hadron Colliders at NNLO of QCD 13m
        Utilizing recent DIS measurements (σ_r, F_{2,3,L}) and data on hadronic dilepton production we determine at NNLO (3-loop) of QCD the dynamical parton distributions of the nucleon generated radiatively from valence-like positive input distributions at an optimally chosen low resolution scale (Q_0^2 < 1 GeV^2) by employing the ``fixed flavor number factorization scheme'' (FFNS). These are compared with ``standard'' NNLO distributions at some fixed and higher resolution scale (Q_0^2 > 1 GeV^2). The NNLO corrections imply in both approaches an improved value of χ^2, typically χ^2_NNLO~ 0.9χ^2_NLO. The dynamical NNLO uncertainties are somewhat smaller than the NLO ones and both are, as expected, smaller than those of their ``standard'' counterparts. The dynamical predictions for F_L(x,Q^2) become perturbatively stable already at Q^2 = 2 - 3 GeV^2 where precision measurements could even delineate NNLO effects in the very small-x region. We obtain α_s(M_Z^2) = 0.1124 ± 0.0020 to be compared with 0.1145 ± 0.0018 at NLO. Using these NNLO dynamical parton distributions in the FFNS as input, we generate radiatively parton distributions in the ``variable flavor number factorization scheme'' (VFNS) as well, where also the heavy quark flavors (c,b,t) become massless partons within the nucleon. Only within the VFNS are NNLO calculations feasible at present, since the required partonic subprocesses are available only in the approximation of massless initial-state partons. The NNLO predictions for gauge boson production are typically larger (by more than 1σ) than the NLO ones, and rates at LHC energies can be predicted with an accuracy of about 5%, whereas at Tevatron they are more than 2σ above the NLO ones. The NNLO predictions for SM Higgs boson production via the dominant gluon fusion process have a total (pdf and scale) uncertainty of about 10% at LHC which almost doubles at the lower Tevatron energies; these predictions are typically about 20% larger than the ones at NLO but the total uncertainty bands overlap.
        Speaker: Dr. Pedro Jimenez-Delgado (University of Zürich)
        Slides
      • 15:05
        PDF sensitivity studies using electroweak processes at LHCb 13m
        We summarise the results from early LHCb data for muon final states produced through the Drell-Yan process via W, Z and gamma* down to a Q2 of 10 GeV2. Extrapolating these results up to the sample sizes expected in the remainder of the 2010 run gives exciting prospects for parton density function studies, which will benefit from LHCb’s unique ability to trigger on low momentum objects. Due to the forward acceptance of LHCb x values down to 2 × 10−6 can be probed, where with just 100 pb−1 of data the gluon PDF can be constrained down to 10%.
        Speaker: Dr. Ronan McNulty (UNIVERSITY COLLEGE DUBLIN)
        Slides
      • 15:20
        Consistency of neutrino DIS and the present parton distribution functions. 13m
        We study the nuclear effects in the neutrino\antineutrino-nucleon deep inelastic scattering (DIS) by comapring the NuTeV, CDHSW, and CHORUS cross-sections from Iron and Lead targets to the predictions derived from the latest parton distribution functions (PDFs). The nuclear modifications found seem to display agreement with those in charged lepton DIS. Our study thus lends support to the consistency of employing neutrino data in global fits of PDFs.
        Speaker: Dr. Hannu Paukkunen (University of Santiago de Compostela)
        Slides
      • 15:35
        Combination and QCD Analysis of the HERA F2^cc Results 10m
        Combination of F2^cc from DIS measurements at HERA The charm contribution F2^cc to the proton structure function F2 is determined. The results of D meson production cross section measurements are combined with the measurements using semi-leptonic decays into muons as well as inclusive track measurements. The correlations of the systematic uncertainties between different measurements are taken into account. The data cover the kinematic range of photon virtuality 2 < Q^2 < 1000 GeV^2 and Bjorken scaling variable 10^-5 < x < 10^-1. PDF fits including F2^cc data The combined H1 and ZEUS data on inclusive ep cross-sections together with the combined data on the semi-inclusive structure function F2(charm) are used to extract the parton densities of the proton at NLO. The inclusion of the F2(charm) data allows detailed tests of the heavy flavour treatment in various QCD calculations.
        Speaker: Massimo Corradi (INFN, Sezione di Bologna)
        Slides
    • 14:00 15:45
      05 - Heavy Quarks Properties (experiment and theory) Salle 242 ()

      Salle 242

      Convener: Alex Bondar (Budker Institute for Nuclear Physics (INP))
      • 14:00
        New measurement of b-hadron lifetimes at CDF 15m
        We report new, world-leading measurements of b-hadron lifetimes and their ratios using B+->J/ψ K+ , B0->J/ψ K0*, B0->J/ψ K0s and Λb->J/ψ Λ, decays reconstructed in a data sample corresponding to 4.3 fb-1 collected by the CDF experiment. A detailed resolution model provides improved systematic uncertainties on the lifetimes, and determination of the b hadron decay-length using only the J/ψ decay-vertex, common to all modes, allow cancellation of the major systematic uncertainties in their ratios.
        Speaker: Juan Pablo Fernandez (CIEMAT)
        Slides
      • 14:15
        New suppressed decays of B0_s mesons 15m
        We present new measurements of suppressed decays of the B0s meson to J/ψ final states at CDF. Using a data sample corresponding to an integrated luminosity of 5 fb-1 of proton-antiproton collisions at sqrt(s)=1.96 TeV, we utilize a low transverse-momentum dimuon trigger to acquire a large sample of J/ψ->µ+µ- decays. We form fully reconstructed B0s candidates using information from the central tracking system and present results on the following decay modes: B0s->J/ψ K*(892), B0s->J/ψ f0(980) and B0s->J/ψ K0s. All of these modes have the possibility of providing further information on lifetime difference and CP asymmetries in B0s decays.
        Speaker: Olga Norniella (UIUC)
        Slides
      • 14:30
        Measurement of Branching Fraction for B_s -> J/psi f_0(980) and Search for B_s -> hh decays 15m
        We present a measurement of the branching fraction for the CP eigenstate decay Bs->J/ψ f0(980). The result is based on 23.6 fb-1 of data collected at the Y(5S) resonance with the Belle detector at the KEKB asymmetric e+e- collider. We have also searched for Bs0->hh decays, where h stands for a charged or neutral kaon, or a charged pion. We observe the decay Bs0->K+K- and measure its branching fraction, Br(Bs0->K+K-)=(3.8 -0.9/+1.0 (stat.) ± 0.5(syst.) ± 0.5(fs))*10-5. No significant signals are seen in other decay modes, and we set upper limits at the 90% confidence level: Br(Bs0->K- π+)<1.2*10-5, Br(Bs0->π+ π-)<2.6*10-5 and Br(Bs0->K0 K0bar)<6.6*10-5.
        Speaker: Jean Wicht (KEK)
        Slides
      • 14:45
        Observation of B_s -> D_s^*- pi+, B_s -> D_s^(*)- rho+ and B_s -> D_s^(*)+ D_s^(*)- and Estimate of Delta Gamma_CP at Belle 15m
        The large data sample being recorded with the Belle detector at the Y(5S) energy provides a unique opportunity to study the poorly-known Bs meson decays. Following our recent measurement of Bs->Ds π in a sample of 23.6 fb-1, we extend the analysis to include decays with photons in the final state. Using the same sample, we report the first observation of three other dominant exclusive Bs decays, in the modes Bs->Ds-* π+, Bs->Ds- ρ+ and Bs->Ds-* ρ+. We measure their respective branching fractions and, using helicity-angle distributions, the longitudinal polarization fraction of the Bs->Ds-* ρ+ decay. We also present a measurement of the branching fractions for the decays Bs->Ds+* Ds-*. In the heavy quark limit, this branching fraction is directly related to the width difference between the CP-odd and CP-even Bs states.
        Speaker: Ms. Sevda Esen (University of Cincinnati)
        Slides
      • 15:00
        Measurement of the Branching Fractions of the Decays B -> Dbar^(*) D^(*) K 15m
        We present a measurement of the branching fractions of the 22 decay channels B0 and B+ to Dbar^(*) D^(*) K, where Dbar^(*) and D^(*) are fully reconstructed. The B0 and B+ mesons are reconstructed in a sample of hadronic events for all the possible Dbar D K modes, namely B0 -> D^(*)- D^(*)0 K^+, D^(*)-D^(*)+ K^0, Dbar^(*)0 D^(*)0 K0 and B^+ -> Dbar^(*)0 D^(*)+ K0, Dbar^(*)0 D^(*)0 K+, D^(*)- D^(*)+ K+. The results are based on 423 fb-1 of data that contained 465 10^6 BBbar pairs collected at the Upsilon(4S) resonance with the BaBar detector at the PEP-II B factory.
        Speaker: Vincent Poireau (LAPP CNRS)
        Slides
      • 15:15
        Observation and study of LambdaC decays of neutral B mesons 15m
        In a sample of 467 million BBbar pairs collected with the BaBar detector at the PEP-II collider at SLAC we have observed the decay B0bar->Λc+ pbar π0 and measured its branching fraction. We determine an upper limit for the branching fraction of the decay B0bar->Λc+(2455) pbar and observe an enhancement at the threshold of the invariant mass of the baryon-antibaryon pair. We also report the observation of the baryonic decay B0bar->Λc+ Λbar K-.
        Speaker: Thomas Hartmann (University of Rostock)
        Slides
    • 14:00 15:45
      08 - Heavy Ion Collisions and Soft Physics at Hadron Colliders Salle 253 ()

      Salle 253

      Convener: Eduardo Fraga (Universidade Federal do Rio de Janeiro)
      • 14:00
        The Color Glass Condensate at NLO: Phenomenology at HERA, RHIC and the LHC. 16m
        The Color Glass Condensate is the effective theory of QCD for high energy scattering. The recent theoretical progress achieved through the calculation of next-to-leading order corrections to the small-x renormalization group equations has opened up a period for precision CGC phenomenology. I shall present CGC analyses of experimental data for the inclusive structure functions in electron-proton scattering as measured in HERA. Next I shall present a description of inclusive particle production measurements in high energy proton-proton, deuteron-gold and gold-gold collisions carried out at RHIC. Together, these works yield a consistent picture that present experiments can probe the non-linear part of the hadronic and nuclear wave functions at small-x, and that they can be successfully described by the CGC effective theory. Prospects for both the proton-proton and heavy ions programs at the LHC will be discussed.
        Speaker: Dr. Javier Albacete (IPhT-CEA-Saclay)
        Slides
      • 14:20
        The present status of the EPS nuclear PDFs 16m
        The recent global analyses of the nuclear parton distribution functions lend support to the validity of the factorization theorem of QCD in high-energy processes involving bound nucleons. With special attention on the recent global analysis EPS09, we review the latest developements in the domain of nuclear PDFs.
        Speaker: Dr. Hannu Paukkunen (University of Santiago de Compostela)
        Slides
      • 14:40
        Azimuthal correlations of forward di-pions in d+Au collisions suppressed by saturation 12m
        The STAR collaboration has recently measured the azimuthal correlation function of forward di-pions. The data show a disapearance of the away-side peak in central d+Au collisions, compared to p+p collisions. We argue that this effect, absent at mid-rapidity, is a consequence of the small-x evolution into the saturation regime of the Gold nucleus wave function, and we show that the data can be quantitavely described in the Color Glass Condensate framework. This confirmation that forward monojets are produced in central d+Au collision is a concrete evidence for parton saturation.
        Speaker: Dr. Cyrille Marquet (Theory Division - CERN)
        Slides
      • 14:55
        QCD Factorization at Forward Rapidities 12m
        We analyze several reactions on nuclear targets at forward rapidities and different energies (at smallest experimentally accessible Bjorken x). Nuclear effects are usually interpreted as a result of shadowing or the Color Glass Condensate. QCD factorization of soft and hard interactions requires the nucleus to be an universal filter for different Fock components of the projectile hadron. We demonstrate, however, that this is not the case in the vicinity of the kinematic limit, x→1, where sharing of energy between the constituents becomes an issue. The rise of suppression with x is confirmed by the E772 and E886 data on the Drell-Yan and heavy quarkonium production. We show that this effect can be treated alternatively as an effective energy loss proportional to initial energy. This leads to nuclear suppression at any energy, and predicts of Feynman x_F scaling of the suppression. We demonstrate also that the same kinematic limit can be approached in transverse momentum when the Cronin enhancement of particle production at medium-high p_T switches to a suppression at larger p_T violating thus QCD factorization. Such an unexpected effect seems to be confirmed by data for pion production in d+A collisions at RHIC, and even for direct photons. We show that this effect also brings significant corrections to all calculations for jet quenching in heavy ion collisions at RHIC. References [1] B.Z. Kopeliovich, J. Nemchik, I.K. Potashnikova, M.B. Johnson and I. Schmidt, Phys. Rev. C72, 054606 (2005); e-Print: hep-ph/0501260. [2] B.Z. Kopeliovich, J. Nemchik, I.K. Potashnikova, M.B. Johnson and I. Schmidt, Nucl. Phys. Proc. Suppl. 146, 171 (2005). [3] J. Nemchik, V. Petracek, I. K. Potashnikova and M. Sumbera, Phys. Rev. C78, 025213 (2008); e-Print: arXiv:0805.4267 [hep-ph]. [4] J. Nemchik and I.K. Potashnikova, AIP Conf. Proc. 1056, 207 (2008); e-Print: arXiv:0807.1605 [hep-ph]. [5] J. Nemchik and M.Sumbera, Proceedings of Science [High-pT physics 09] ISSN 1824-8039 (2009) 042. [6] J. Nemchik and M. Sumbera, Nucl. Phys. A 830, 611C (2009); e-Print: arXiv:0907.4062 [hep-ph]].
        Speaker: Dr. Michal Sumbera (Nuclear Physics Institute ASCR-Acad. of Sciences of the Czech Re)
        Slides
      • 15:10
        Inclusive Photoproduction of ρº, K*º and φ Mesons at HERA 12m
        Inclusive non-diffractive photoproduction of ρ(770)º, K*(892)º and φ(1020) mesons is investigated with the H1 detector in ep collisions at HERA. The corresponding average gamma p centre-of-mass energy is 210 GeV. The mesons are measured in the transverse momentum range 0.5 < pT < 7 GeV and the rapidity range |y_lab|<1. Differential cross sections are presented as a function of transverse momentum and rapidity, and are compared to the predictions of hadroproduction models.
        Speaker: Andrei Rostovtsev (ITEP Institute for Theoretical and Experimental Physics (ITEP)-U)
        Slides
      • 15:25
        Refining Geometrical Scaling 16m
        We consider and compare various geometric-scaling solutions of the QCD Balitsky-Kovchegov (BK) equation, for fixed or running QCD coupling. These solutions predict different scaling variables which we first test with recent DIS cross-section data using the "Quality Factor" method. Then we use a chi^2 method to compare the different predicted parametrisations of the traveling wave representation of the BK equation's solutions. A geometric scaling corresponding to running coupling is finally favored, with a satisfactory chi^2 by d.o.f.. There is no indication of a sizeable scaling violation term.
        Speaker: Robi Peschanski (IPhT, CEA-Saclay)
        Slides
    • 14:00 15:45
      12 - Beyond Quantum Field Theory Approaches (including String Theories) Salle 252A ()

      Salle 252A

      Convener: Iosif Bena (CEA-Saclay)
      • 14:00
        Gravity as an Emergent Force 37m
        Starting from first principles and general assumptions Newton's law of gravitation is shown to arise naturally and unavoidably in a theory in which space is emergent through a holographic scenario. Gravity is explained as an entropic force caused by changes in the information associated with the positions of material bodies. A relativistic generalization of the presented arguments directly leads to the Einstein equations. When space is emergent even Newton's law of inertia needs to be explained. The equivalence principle leads us to conclude that it is actually this law of inertia whose origin is entropic.
        Speaker: Prof. Erik Verlinde (ITP, University of Amsterdam)
        Slides
      • 14:42
        Quantum entropy function 18m
        In this talk we shall describe how quantum entropy function formalism allows us to compute classical, perturbative and non perturbative contribution to the extremal black hole entropy. We shall also compare the results with microscopic results.
        Speaker: Ashoke Sen (Harish-Chandra Research Institute)
        Slides
      • 15:03
        Multicentered Microstates and Large Quantum Fluctuations 18m
        We quantize a family of smooth multicentered supergravity solutions generating (micro)states of a large supersymmetric black hole in five dimensions. Certain special states are found to suffer from unexpected, macroscopically large quantum fluctuations in the near horizon region of the putative black hole. This breakdown in effective field theory near the horizon may be relevant in resolving black hole paradoxes and hence warrants further study. We report on on-going attempts to re-introducing "stringy" degrees of freedom in the near horizon region, continuing these solutions (by virtue of a non-renormalization theorem) to a weakly coupled D-brane quantum mechanics, where addition degrees of freedom, unapparent in supergravity, may be more tractably studied.
        Speaker: Dr. Sheer El-Showk (CEA Saclay)
        Slides
      • 15:24
        Classical solutions of open string field theory 18m
        We review recent progress in finding and analyzing classical solutions of open string field theory.
        Speaker: Dr. Martin Schnabl (Institute of Physics AS CR, Prague)
        Slides
    • 15:45 16:15
      Coffee Break 30m
    • 16:15 18:15
      01 - Early Experience and Results from LHC Salle Maillot ()

      Salle Maillot

      Convener: Thomas Ruf (CERN)
      • 16:15
        Material Studies with Photon Conversions and Energy Flow at the ATLAS Experiment 15m
        With the start of the LHC operations at at center of mass energy of 7 TeV a large sample of low energy photons, mostly coming from the decay of neutral mesons, have been collected with the ATLAS detector. Due to the large amount of material upstream the electromagnetic (EM) calorimeter, about 50% of these photons will convert before reaching it. The converted photons are used as a tool to map the material of the ATLAS tracker in front of the EM calorimeter. The results of the material measurements relative to an accurately measured reference volume inside the tracker, together with an estimate of the most important sources of systematic uncertainties will be shown. The effect of the energy loss due to bremsstrahlung on the conversion vertex reconstruction precision is also discussed. The results from using the extremely pure electron sample provided by the converted photons to study the particle identification capabilities of the ATLAS Transition Radiation Tracker (TRT), are presented. Furthermore, the measurement of the energy flow in the electromagnetic calorimeter (EM) is typically used to spot early detector problems, but it is also sensitive to the (radially integrated) amount of material in front of the electromagnetic calorimeter. Using the LHC collision data collected at a centre of mass energy of 7 TeV, the two dimensional (eta versus phi) occupancy maps of the EM calorimeter for each longitudinal layer have been extracted. Such a method provides a cross check of the total amount of material in front of the calorimeter and it is complementary to others only sensitive to the amount of material in the tracker. The measurement accuracy will be dominated by the systematic uncertainties and the ultimate accuracy is expected to be about 5% of the material upstream.
        Speaker: Anthony Morley (CERN)
        Slides
        Video
      • 16:35
        Performance of Jet, Missing Transverse Energy and Tau Reconstruction with ATLAS in pp Collisions at √s = 7 TeV 15m
        This talk presents the first results on jet, missing transverse energy (MET) and tau reconstruction performance, as obtained with the ATLAS detector in 7 TeV proton-proton collisions at the LHC. Jets are reconstructed with the anti-kt jet algorithm using calorimeter clusters, or as so called 'track jets' using the Inner Detector only. The performance of the jet reconstruction will be compared to the Monte Carlo expectation. Methods to determine the jet energy scale and resolution will also be discussed. The MET performance has been studied in randomly-triggered events, soft proton proton collisions and collisions with jets at high transverse momentum where MET is expected to be zero. First MET measurements are also presented for events where a W-boson is produced. Finally, a status of tau reconstruction, identification and triggering in ATLAS will be given.
        Speaker: Ariel Schwartzman (SLAC National Accelerator Laboratory)
        Slides
        Video
      • 16:55
        Performance of Jet and Missing Transverse Energy Reconstruction with CMS in pp Collisions at √s = 7 TeV 15m
        Data from pp collisions have been used to study jets and missing transverse energy (MET) in the CMS experiment at the Large Hadron Collider. Results are presented for four different approaches to reconstruct jets and three different approaches to reconstruct MET in The CMS detector: calorimeter-only based jet and MET reconstruction; an algorithm which improves the measurement of calorimeter jets and MET by exploiting the associated tracks; the “Particle Flow” method, which reconstructs each particle in the event based on information from all sub-detectors, prior to the clustering of jets or the calculation of MET; and jets reconstructed from tracks only. The results are compared to those from fully simulated Pythia events. For MET the performance is studied using inclusive pp interactions and also exclusive states such as events containing two high transverse momentum jets, W bosons, Z bosons or isolated, high transverse momentum photons in 7-TeV proton-proton collisions. For jets, pT balance in dijet and photon+jet events is used to measure the jet response as function of pseudorapidity, absolute jet response in the central pseudorapidity region, and jet resolution in multiple regions. Further, we present measurements of the offset energy from noise and pile-up in a jet.
        Speaker: Joanna Weng (CERN)
        Slides
        Video
      • 17:15
        Performance of the particle flow algorithm in CMS 15m
        The aim of the CMS particle flow event-reconstruction algorithm is to identify and reconstruct individually each particle arising from the LHC proton-proton collision, by combining the information from all subdetectors. The resulting particle-flow event reconstruction leads to an improved performance for the reconstruction of jets and MET, and for the identification of electrons, muons, and taus. The 7 TeV jet data, as well as leptons from J/Psi, W and Z Boson are used to finalize the commissioning of the particle-flow algorithm. The efficient reconstruction and identification of photons, charged and neutral hadrons, muons and electrons made possible by the versatility of the CMS apparatus, are shown to perform as expected up to a high level of precision. Results on particle-based jets and missing transverse energy, as well as on muons and electrons obtained through the reconstruction of standard candles are shown.
        Speaker: Dr. Florian Beaudette (CERN)
        Slides
        Video
      • 17:35
        Performance of CMS muon reconstruction in pp collisions at √s = 7 TeV 20m
        The performance of muon reconstruction in CMS has been studied on a sample of muons collected in pp collisions at √s = 7 TeV at the LHC. Measured distributions of basic muon-track quantities are well reproduced by the Monte Carlo simulation. Efficiencies of various high-level trigger, identification, and reconstruction algorithms have been measured and compared with the expectations from Monte Carlo simulation. Results for the relative muon momentum resolution and the muon momentum scale will be reported.
        Speaker: Giovanni Petrucciani (Univ. of California, San Diego)
        Slides
        Video
      • 17:55
        Performance of the ATLAS Muon Spectrometer and of Muon Identification at the LHC 20m
        The large cosmic data samples collected in fall 2009 by the ATLAS experiment have been used to study the performance of the Muon Spectrometer. Detailed studies of the basic Muon spectrometer performance in terms of sagitta resolution, tracking efficiency and momentum resolution are presented and provide an update with respect to the results recently published. The results are also compared with a cosmic data simulation recently improved with a more realistic drift chamber response. The recent collision data collected at a CM of 7 TeV have also been analyzed to determine basic Muon Spectrometer performance. The performance of the ATLAS muon identification was studied with 1 inverse nanobarn of LHC proton-proton collision data at a centre of mass energy of 7 TeV. Measured detector efficiencies, hit multiplicities, and residual distributions of reconstructed muon tracks are well reproduced by the Monte Carlo simulation. Exploiting the redundancy in the muon identification at detector and reconstruction level the performance of the identification steps could be checked with data. 4.5 muons per microbarn with pT > 6 GeV and |η|<2.5 were identified as predicted by Pythia minimum bias Monte Carlo. The pseudorapidity, ϕ, and pT distributions of the reconstructed muons are in reasonable agreement with the Monte Carlo prediction.
        Speaker: Martin Woudstra (University of Massachusetts)
        Slides
        Video
    • 16:15 18:00
      02 - The Standard Model and Electroweak Symmetry Breaking Salle 252B ()

      Salle 252B

      Convener: Giampiero Passarino (Torino University)
      • 16:15
        Higgs production at the Tevatron: theoretical predictions and uncertainties 22m
        I will present an update of the theoretical predictions for the production cross sections of the Standard Model Higgs boson at the Tevatron collider. The two main search channels will be discussed, the gluon-gluon fusion mechanism gg → H and the Higgs-strahlung process q qbar → VH with V=W/Z, including all relevant higher order QCD and electroweak corrections in perturbation theory. A thorough analysis of the various uncertainties affecting these predictions will then follow.
        Speaker: Mr. Julien Baglio (Theoretical Physics Laboratory, Orsay)
        Slides
      • 16:40
        Standard Model low mass Higgs search at CDF 18m
        We have searched for the Standard Model Higgs boson in the low mass region using CDF detector at the Tevatron. Results with over 5 fb-1 of integrated luminosity will be presented.
        Speaker: Yoshikazu Nagai (FNAL)
        Slides
      • 17:00
        Standard Model low mass Higgs search at DZero 18m
        We have searched for the Standard Model Higgs boson in the low mass region using DZero detector at the Tevatron. Results with over 6 fb-1 of integrated luminosity will be presented.
        Speaker: Yuji Enari (LPNHE Paris Universtat VI&VII)
        Slides
      • 17:20
        Standard Model high mass Higgs search at CDF 18m
        We have searched for the Standard Model Higgs boson in the high mass region using CDF detector at the Tevatron. Results with over 5 fb-1 of integrated luminosity will be presented.
        Speaker: Dr. Donatella Lucchesi (INFN Padova)
        Slides
      • 17:40
        Standard Model high mass Higgs search at DZero 18m
        We have searched for the Standard Model Higgs boson in the high mass region using DZero detector at the Tevatron. Results with up to 7 fb-1 of integrated luminosity will be presented.
        Speaker: Boris Tuchming (CEA Saclay)
        Slides
    • 16:15 18:00
      04 - Hadronic Structure, Parton Distributions, soft QCD, Spectroscopy Salle 251 ()

      Salle 251

      Convener: Enrico Tassi (Dipartimento di Fisica-Univ. degli Studi della Calabria)
      • 16:15
        Combination and QCD Analysis of the HERA Inclusive Cross Sections 18m
        Combined Measurement of Neutral and Charged Current Cross Sections at HERA A combination is presented of the inclusive cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current deep-inelastic ep scattering at HERA. The combination uses data from unpolarised ep scattering taken during the HERA-I phase as well as measurements with longitudinally polarised electron or positron beams from the HERA-II running period. The combination method takes the correlations of systematic uncertainties into account. The inclusion of the large HERA-II data set leads to an improved uncertainty especially at large four momentum transfer squared Q^2. Combined measurement of the Inclusive e+p Scattering Cross Sections at HERA for Reduced Proton Beam Energy Runs and Determination of the Structure Function F_L A combination of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations for ep scattering with nominal and reduced proton-beam energies, Ep=920 GeV, Ep=460 GeV and 575 GeV, is presented. The combination method used takes the correlations of systematic uncertainties into account, resulting in improved accuracy. From the combined data the proton structure function, F_L, is extracted in the region of 2.5 < Q^2 < 800 GeV^2. Combined Measurement and QCD Analysis of the Inclusive ep Scattering Cross Sections at HERA A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised ep scattering at HERA during the period 1994-2000. The data span six orders of magnitude in negative four-momentum-transfer squared, Q^2, and in Bjorken x. The combination method used takes the correlations of systematic uncertainties into account, resulting in an improved accuracy. The combined data are the sole input in a NLO QCD analysis which determines a new set of parton distributions, HERAPDF1.0, with small experimental uncertainties. This set includes an estimate of the model and parametrisation uncertainties of the fit result. PDF fits including HERA data with reduced proton beam energy A QCD fit analysis to the combined HERA-I inclusive deep inelastic cross sections measured by the H1 and ZEUS collaborations for ep scattering, including the HERA-II measurements with reduced proton-beam energies, Ep = 460GeV and Ep = 575GeV, is presented. The effect of including the new data on the determination of HERA parton distribution functions is analysed, using fits similar to those performed for HERAPDF1.0. Some tension of the QCD fit with respect to the data is identified in the kinematic region of low Q^2 and low x. Furthermore, the data show sensitivity to various schemes of treating heavy flavours. PDF fits including HERA-II high Q^2 data The QCD fit analysis of the combined HERA-I inclusive deep inelastic cross sections has been extended to include combined HERA II measurements at high Q^2. The effect of including these data on the determination of parton distribution functions is analysed, using fits similar to those performed for HERAPDF1.0. The precision of the PDFs at high-x is considerably improved- particularly in the valence sector.
        Speaker: Voica Ana Maria Radescu (Deutsches Elektronen Synchrotron (DESY))
        Slides
      • 16:35
        Charm and Beauty Production from Secondary Vertexing at HERA 18m
        Measurement of the Charm and Beauty Structure Functions using the H1 Vertex Detector at HERA Inclusive charm and beauty cross sections are measured in e^- p and e^+p neutral current collisions at HERA in the kinematic region of photon virtuality 5 < Q^2 < 2000 GeV^2 and Bjorken scaling variable 0.0002 < x < 0.05. The data were collected with the H1 detector in the years 2006 and 2007 corresponding to an integrated luminosity of 189 pb^-1. The numbers of charm and beauty events are determined using variables reconstructed by the H1 vertex detector including the impact parameter of tracks to the primary vertex and the position of the secondary vertex. The measurements are combined with previous data and compared to QCD predictions. Measurement of Charm and Beauty Jets in Deep Inelastic Scattering at HERA Measurements of the charm and beauty jet cross sections have been made in deep inelastic scattering at HERA for the kinematic region of photon virtuality Q^2 > 6 GeV^2 and elasticity variable 0.07 < y < 0.625 for jets in the laboratory frame with transverse energy E_T^jet > 6 GeV and pseudorapidity -1.0 < eta^jet < 1.5. Measurements are also made requiring a jet in the Breit frame with E_T^jet > 6 GeV. The data were collected with the H1 detector in the years 2006 and 2007 corresponding to an integrated luminosity of 189 pb^-1. The number of charm and beauty jets are determined using variables reconstructed by the H1 vertex detector including the impact parameter of tracks to the primary vertex and the position of the secondary vertex. The measurements are compared with QCD predictions and with previous measurements obtained using muon tagging. Charm and beauty production in deep inelastic scattering from inclusive secondary vertexing at ZEUS Charm and beauty production in deep inelastic scattering has been measured with the ZEUS detector using the full HERA II data set. The charm and beauty contents in events with a jet have been extracted using the decay length significance and invariant mass of secondary decay vertices. Differential cross sections as a function of Q^2, Bjorken x, p_T(jet) and eta(jet) were measured and compared to theoretical predictions. The open charm and beauty contributions to the proton structure function F_2 are extracted. Measurement of charm and beauty photoproduction from inclusive secondary vertexing at HERA-II Photoproduction of beauty and charm quarks in events with two jets has been measured with the ZEUS detector at HERA using an integrated luminosity of 130 pb-1. The beauty and charm content was extracted using the decay-length significance of the b and c hadrons and the invariant mass of the decay vertices. Differential cross sections as functions of pT(Jet) and eta(Jet) are compared with the Pythia leading order plus parton shower (LO+PS) Monte Carlo and QCD predictions calculated at next-to-leading order.
        Speaker: Dr. Paul Thompson (University of Birmingham)
        Slides
      • 16:55
        Charm and Beauty Production from Semileptonic Decays at HERA 18m
        Measurement of the photoproduction of b-quarks at threshold at HERA The cross section of bb_bar photoproduction in ep collisions is measured with the H1 detector at HERA. Events containing b-quarks are identified through detection of two low momentum electrons in the final state. Semileptonic decays bb_bar -> ee X are exploited in the kinematic range of the photon virtuality Q^2 < 1 GeV^2, the inelasticity 0.2 < y < 0.8 and the pseudorapidity of the b-quarks |eta(b), eta(b_bar)| < 2. The differential b-quark production cross section is measured as a function of the transverse b-quark momentum and extends the previously experimentally accessible phase space towards the b-quark production threshold. The results are compared to other b-quark cross section measurements, as well as to QCD predictions. Measurement of charm and beauty production in deep inelastic ep scattering from decays into muons at HERA The production of charm and beauty quarks in ep interactions has been measured with the ZEUS detector at HERA for squared four-momentum exchange Q^2>20 GeV^2, using an integrated luminosity of 126 pb^-1. Charm and beauty quarks were identified through their decays into muons. Differential cross sections were measured for muon transverse momenta p_T^μ>1.5 GeV and pseudorapidities -1.6<eta^μ<2.3, 114="" a="" agree="" also="" an="" and="" are="" as="" at="" based="" bbar="" beauty="" been="" bjorken="" by="" charm="" contributions="" cross="" data="" deep="" described="" detector="" determined="" dis="" distribution="" eta^μ,="" events="" extracted.="" extraction="" f2b="" f_2="" final="" for="" fraction="" function="" has="" hera="" in="" independent="" inelastic="" integrated="" jet="" jet.="" kinematic="" luminosity="" measured="" measurement="" measurements="" momentum="" muon="" observed="" of="" on="" p_t^μ,="" pb-1.="" photon="" predictions.="" previous="" production="" proton="" q^2="" qcd="" quarks="" range="" relative="" results="" scattering="" section="" state="" structure="" techniques="" the="" to="" transverse="" using="" virtuality,="" was="" well="" were="" which="" with="" x.="" zeus=""> 2 GeV^2, and inelasticity, 0.05 < y < 0.7, with the requirement of a muon and a jet. Total and differential cross sections are presented and compared to QCD predictions. The beauty contribution to the structure function F_2 was extracted and is compared to theoretical predictions. Measurement of beauty production from dimuon events at HERA Beauty production in events containing two muons in the final state has been measured with the ZEUS detector at HERA using an integrated luminosity of 114 pb-1. A low transverse-momentum threshold for muon identification, in combination with the large rapidity coverage of the ZEUS muon system, gives access to a very large fraction of the phase space for beauty production. The total cross section for beauty production in ep collisions at sqrt(s)=318 GeV has been measured to be sigma_tot(ep->b bar X)=13.9+-1.5(stat.)+4.0-4.3(syst.) nb. Differential cross sections and a measurement of bbar correlations are also obtained, and compared to other beauty cross-section measurements, Monte Carlo models and next-to-leading-order QCD predictions. Charm and beauty production with semi-leptonic decay into electrons in DIS and PHP at ZEUS The production of heavy quarks in ep interactions has been studied with the ZEUS detector at HERA in the photoproduction and DIS regimes using an integrated luminosity of 360 pb-1. The heavy flavour events were identified using electrons with a transverse momentum of at least pT(e) > 0.9 GeV in the range eta(e) < 1.5. The fractions of events containing the heavy quarks were extracted from a likelihood fit using variables sensitive to electron identification as well as to semileptonic decays. Total and differential cross sections for beauty, and in the case of photoproduction also for charm, were measured and compared with next-to-leading-order QCD calculations and Monte Carlo models. For squared four-momentum exchange of 10 < Q2 < 1000 GeV2 the beauty contribution to the proton structure function, F2b, was extracted from the double differential cross section as a function of x and Q^2.</eta^μ<2.3,>
        Speaker: Markus Juengst (Universitaet Bonn)
        Slides
      • 17:15
        D* (+jets) in Deep Inelastic Scattering and Photoproduction 13m
        Measurement of the D* Meson Production Cross Section and F_2^ccbar, at High Q^2, in ep Scattering at HERA The inclusive production of D*(2010) mesons in deep-inelastic ep scattering is measured in the kinematic region of photon virtuality 100 < Q^2 < 1000 GeV^2 and inelasticity 0.02 < y < 0.7. Single and double differential cross sections for inclusive D* meson production are measured in the visible range defined by |eta(D*)| < 1.5 and p_T(D*) > 1.5 GeV. The data were collected by the H1 experiment during the period from 2004 to 2007 and correspond to an integrated luminosity of 351 pb^{-1}. The charm contribution, F_2^{ccbar}, to the proton structure function F_2 is determined. The measurements are compared with QCD predictions. Combination of F_2^{ccbar} from D^{*+-} Measurement in DIS and inclusive measurement of displaced tracks at H1 Recent measurements by the H1 experiment of the inclusive charm and beauty cross sections in deep inelastic ep scattering at HERA are presented. The data were collected in the years 2006 and 2007 corresponding to an integrated luminosity of 189 pb^-1. The numbers of charm and beauty events are determined using variables reconstructed by the H1 vertex detector. The measurement of the inclusive charm cross section is combined with the result obtained using the reconstruction of D^{*+-} mesons in order to obtain a more precise measurement of the charm contribution F_2^{ccbar} the proton structure function F_2. The measurements are compared with QCD predictions. D* with jets in photoproduction Photoproduction of events containing a D* meson and two jets are investigated with the H1 detector using the HERA-II data sample. The D* mesons are reconstructed in the golden decay channel D* -> K pi pi_s. Photoproduction events are selected in the kinematic range Q^2 < 2 GeV^2 and 0.1 < y < 0.8 corresponding to 100 < W_gammap < 285 GeV. The jets are reconstructed with the inclusive k_T algorithm in the laboratory frame and are selected if they have p_T > 3.5 GeV. Differential cross section sensitive to the kinematics of the incoming gluon are measured and compared to QCD calculations. D* production in deep inelastic ep scattering at HERA Inclusive production of D*(2010) mesons in deep inelastic ep scattering was studied in the D^0 pi_s decay channel with the ZEUS detector at HERA using an integrated luminosity of 360 pb-1. Differential D* cross sections are presented as functions of the D* transverse momentum, Pt(D*), and pseudorapidity, eta(D*), for 1.5 < Pt(D*) < 15 GeV and |eta(D*)| < 1.5 in the kinematic region of photon virtuality 5 < Q2 < 1000 GeV2 and inelasticity 0.02 < y < 0.7. In addition, differential cross sections for D* production as functions of Q2 and Bjorken x are presented. Next-to-leading-order (NLO) QCD predictions give an adequate description of the data. The measured cross section was extrapolated using these predictions to the full kinematic region in y, Pt(D*) and eta(D*) to determine the open charm contribution to the proton structure function, F2cc. Predictions from NLO QCD fits to inclusive data describe well the extracted F2cc from D* production.
        Speaker: Andreas Werner Jung (DESY)
        Slides
      • 17:30
        D^±, D^0 and Λ_c^+ Production in Deep Inelastic Scattering at HERA 13m
        Measurement of D+- and D0 Production in Deep Inelastic Scattering Using a Lifetime Tag at HERA The production of D+- and D0 mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb-1. The measurements cover the kinematic range 5 < Q2 < 1000 GeV2, 0.02 < y < 0.7, 1.5 < pT(D) < 15 GeV and |eta(D)| < 1.6. Combinatorial background to the D meson signals is reduced by using the ZEUS microvertex detector to reconstruct displaced secondary vertices. Production cross sections are compared with the predictions of next-to-leading-order QCD which is found to describe the data well. Measurements are extrapolated to the full kinematic phase space in order to obtain the open-charm contribution, F2(ccbar), to the proton structure function, F2. Measurement of D+ and Lambda_c+ production in deep inelastic scattering at HERA Charm production in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 120 pb-1. The hadronic decay channels D+ -> K0S pi+, Lambda_c+ -> p K0S and Lambda_c+ -> Lambda pi+, and their charge conjugates, were reconstructed. The presence of a neutral strange hadron in the final state reduces the combinatorial background and extends the measured sensitivity into the low transverse momentum region. The kinematic range is 0 < pT(D+,Λ_c+) < 10GeV, |eta(D+,Λ_c+)| < 1.6, 1.5 < Q2 < 1000GeV2 and 0.02 < y < 0.7. Inclusive and differential cross sections for the production of D+ mesons are compared to next-to-leading-order QCD predictions. The fraction of c quarks hadronising into Lambda_c+ baryons is extracted. Measurement of D+- production production and F2c extraction in deep inelastic scattering at ZEUS The production of charm quarks in deep inelastic ep scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 323 pb-1. Charm events were identified through the D+ -> K- pi+ pi+ (+cc) decay channel. A lifetime tag based on decay length significance was applied to improve the signal to background ratio. The kinematic region was 1.5 < p_T(D+) < 15 GeV, |eta(D+)| < 1.6, 5 < Q^2 < 1000 GeV^2 and 0.02 < y < 0.7. Total and differential cross sections for D+ production were measured and compared to next-to-leading-order QCD calculations and published ZEUS results. The charm contribution to the proton structure function, F2c, was extracted. The results agree with previous measurements and are well described by QCD predictions.
        Speaker: Philipp Roloff (DESY)
        Slides
      • 17:45
        Non-linear QCD dynamics and exclusive production in ep collisions 13m
        The exclusive processes in electron-proton (ep) interactions are an important tool to investigate the QCD dynamics at high energies as they are in general driven by the gluon content of proton which is strongly subject to parton saturation effects. In this paper we compute the cross sections for the exclusive vector meson production as well as the deeply virtual Compton scattering (DVCS) relying on the color dipole approach and considering the numerical solution of the Balitsky-Kovchegov equation including running coupling corrections. We show that the small-x evolution given by this evolution equation is able to describe the DESY-HERA data and is relevant for the physics of the exclusive observables in future electron-proton colliders and in photoproduction processes to be measured in coherent interactions at the LHC.
        Speaker: Dr. Magno Machado (Universidade Federal do Rio Grande do Sul)
        Slides
    • 16:15 18:00
      05 - Heavy Quarks Properties (experiment and theory) Salle 242 ()

      Salle 242

      Convener: Marjorie Corcoran (Rice University)
      • 16:15
        Decay constants of heavy mesons from QCD sum rules 15m
        We study the decay constants of D, Ds, B, Bs mesons with Borel QCD sum rules, making use of the recent modifications related to the Borel-parameter-dependent effective continuum threshold. For the fixed values of the QCD parameters, our modifications are shown to lead to a visible shift of the extracted value of the decay constant compared to the standard analysis based on a Borel-parameter-independent threshold. We argue that our modifications allow one to probe the systematic errors of the extracted decay constants. We provide rather accurate results for fD and fDs. We demonstrate that an accurate extraction of fB and fBs is only possible if a very precise value of m_b(m_b) is known.
        Speaker: Prof. Dmitri Melikhov (HEPHY & SINP)
        Slides
      • 16:30
        The b-quark mass and the heavy-strange decay constant from lattice HQET 15m
        We present our strategy to compute the b-quark mass and the heavy-strange decay constant, in heavy quark effective theory including 1/m corrections. By matching the effective theory and QCD in a small volume, one can determine non-perturbatively the bare parameters of the HQET Lagrangian and those of the heavy-light currents. The static, kinetic and magnetic energy of the heavy-light meson are obtained from large volume simulations. Using the GEVP method applied to all-to-all propagators allows us to isolate the ground state and the first excited state. I will show how the b-quark mass and the heavy-strange decay constant can be computed in this way, and I will present our preliminary results for the case of nf=2 flavors of dynamical quarks.
        Speaker: Dr. Nicolas Garron (University of Edinburgh)
        Slides
      • 16:45
        Are scalar mesons visible in B+- --> pi+ pi- pi+- decays? 15m
        The two-pion effective mass and helicity angle distributions in the charged B-meson decays into three charged pions are studied. The weak decay amplitudes are calculated in the QCD factorization framework. The final state interactions between the produced pairs of pions are described using strong pion-pion scalar and vector form factors. The scalar form factors are constrained by pion-pion, kaon-antikaon and four pion production data incorporated into a multichannel model of the corresponding coupled amplitudes. The pion-pion vector form factor is parametrized as in the Belle Collaboration analysis of their high statistics data on τ-->π- π0 v_τ decays [Phys. Rev. D78 (2008) 072006]. The theoretical distributions of the dipion effective masses are compared with the corresponding results of the recent Dalitz plot analysis of B±->π+ π- π± decays done by the BaBar Collaboration [Phys. Rev. D79 (2009) 072006]. We show that the S-wave dipion amplitude, although much smaller than the P-wave amplitude corresponding to the ρ(770) resonance, plays, nevertheless, an important role in the ρ(770) mass range. As a matter of fact, the interference term between the S and P dipion amplitudes can reach a value as high as 30% of the dominating ρ(770) contribution. This effect can be attributed to the broad f0(600) (σ) meson. The S-wave is also sizeable above 1 GeV where higher scalar resonances exist. The signal of the B±->f0(980) π± decay has not been seen in the experimental analysis, but this can be easily explained in the present model since the relevant B decay amplitude is proportional to the scalar form factor which has a characteristic dip at the f0(980) mass. We show that the helicity angle (theta) distribution is strongly asymmetric in the ρ(770) meson range. This effect is confirmed by the comparison of our results with the BaBar data integrated over cos(θ)>0 or over cos(θ)<0. It would be quite interesting to compare our model with the high statistics data already obtained by the Belle Collaboration and with future data from super B-factories.
        Speaker: Leonard Lesniak (H. Niewodniczanski Institute of Nuclear Physics PAN, Krakow, Poland)
        Slides
      • 17:00
        New results on bottom baryons with the CDF II detector 15m
        We present a high statistics study of Σb bottom baryon states based on a sample corresponding to 5.3 fb-1 of fully reconstructed Λb decays collected by the CDF experiment. The first independent mass and widths measurements of all four states Σb*+ and Σb*- are reported.
        Speaker: Dr. Igor Gorelov (Univ. of New Mexico, USA.)
        Slides
      • 17:15
        Measurement of the inclusive b production cross section in pp collisions at sqrt(s) = 7 TeV 15m
        Measurements by the CMS experiment of the cross section for inclusive b production in proton-proton collisions at sqrt(s) = 7 TeV are presented. The measurements are based on different methods, such as inclusive jet measurements with secondary vertex tagging or selecting a sample of events containing jets and at least one muon, where the transverse momentum of the muon with respect to the closest jet axis discriminates b events from the background. The data are compared with QCD Monte Carlo predictions at LO and NLO accuracy.
        Speaker: Lea Michaela Caminada (Institut fuer Teilchenphysik - ETHZ)
        Slides
      • 17:30
        Measurement of beauty photoproduction using decays into muons in dijet events at HERA 15m
        Beauty photoproduction in dijet events has been measured at HERA with the ZEUS detector using an integrated luminosity of 126 pb-1. Beauty was identified in events with a muon in the final state by using the transverse momentum of the muon relative to the closest jet. Lifetime information from the silicon vertex detector was also used; the impact parameter of the muon with respect to the primary vertex was exploited to discriminate between signal and background. Cross sections for beauty production as a function of the muon and the jet variables as well as dijet correlations are compared to QCD predictions and to previous measurements. The data are well described by predictions from next-to-leading-order QCD.
        Speaker: Achim Geiser (Fachbereich Physik)
        Slides
    • 16:15 18:00
      08 - Heavy Ion Collisions and Soft Physics at Hadron Colliders Salle 253 ()

      Salle 253

      Convener: Raphael Granier De Cassagnac (Ecole Polytechnique, CNRS-IN2P3)
      • 16:15
        LHC data confront Monte Carlo predictions 20m
        In this talk Monte Carlo models for Minimum Bias physics and their corresponding tunes will be confronted with data from the LHC.
        Speaker: Frank Krauss (Durham)
        Slides
      • 16:40
        Identified particle spectra measured by the ALICE experiment in pp collisions at 0.9 and 7 TeV at LHC. 16m
        We will present the transverse momentum spectra of identified particles measured with the ALICE experiment in proton-proton collisions at LHC recorded at the center-of-mass energies of 0.9 and 7 TeV. The spectra of the charged particles (π± , K± , p and pbar) were obtained measuring the dE/dx in the ALICE TPC and ITS complemented at higher momenta by the time-of-flight information provided by the ALICE TOF detector. The spectra of the Kº_S, and hyperons were reconstructed using the decay topology of these particles. These measurements demonstrate the exceptional operation of both the LHC machine and the ALICE experiment. On the physics side, they provide insights about the mechanisms of the particle production at these energies and will serve as a baseline for the future measurements at even higher LHC energies and for heavy-ion collisions.
        Speaker: Dr. Mercedes Lopez Noriega (IPNO)
        Slides
      • 17:00
        Measurements of Hadron Production at CMS 16m
        We report on measurements of hadron production in pp collisions at √s = 0.9, 2.36 and 7 TeV, recorded with the CMS detector. Transverse momentum, pseudorapidity and multiplicity distributions of charged hadrons are presented. For non-single diffractive collisions, the average charged-hadron transverse momentum and pseudorapidity density near mid-rapidity are compared with other measurements in ppbar and pp collisions. To extend the statistical reach of the measurements of charged hadron transverse momentum spectra, calorimeter-based high-ET jet triggers are employed to enhance yields at high pT. Finally, measured spectra of identified hadrons are presented. The charged pions, kaons and protons are identified with help of their energy loss in the silicon tracker, while the K°s and lambda and anti-lambda are reconstructed based on their decay topology. The obtained rapidity and pT spectra, as well as per event yields are compared to theoretical models. The energy dependence of the above quantities is also studied.
        Speaker: Keith Ulmer (University of Colorado)
        Slides
      • 17:20
        Charged particle multiplicities in inelastic pp events with the ATLAS detector 16m
        The measurement of the properties of proton-proton interactions at center-of-mass energies ranging from 900 GeV (injection energy) to 7 TeV in the ATLAS detector are presented. The charged-particle density, its dependence on transverse momentum and pseudo-rapidity, and the relationship between transverse momentum and charged-particle multiplicity are measured for events with at least one charged particle in a defined kinematic range. The measurements are compared to Monte Carlo models for inelastic events and to results from other experiments.
        Speaker: Alison Lister (University of Geneva)
        Slides
      • 17:40
        Measurements of Two-Particle Correlations in pp collisions 16m
        We present results on two-particle angular correlations in proton-proton collisions over a broad range of pseudorapidity (Δη) and azimuthal angle (Δφ). The data were collected with the CMS detector. A complex two-dimensional correlation structure in Δη and Δφ is observed. In the context of an independent cluster model of short-range correlations, the cluster size and its decay width are extracted from the two-particle pseudorapidity correlation function and compared with previous measurements in proton-proton and proton-antiproton collisions, as well as PYTHIA predictions. The results at 0.9 TeV are in agreement with previous measurements. The new results at 2.36 and 7 TeV represent the highest-energy measurements at a particle collider to date. Furthermore, Bose-Einstein correlations have been measured using samples of proton-proton collisions at 0.9 and 2.36 TeV center-of-mass energy. The signal is observed in the form of an enhancement of pairs of same-sign charged particles with small relative four-momentum. A significant increase of the size of the correlated particle emission region with the particle multiplicity in the event is observed.
        Speaker: Dr. Stefano Lacaprara (INFN Padova)
        Slides
    • 16:15 18:00
      12 - Beyond Quantum Field Theory Approaches (including String Theories) Salle 252A ()

      Salle 252A

      Convener: Alessandro Tomasiello (Milan Bicocca University)
      • 16:15
        Holography for Schroedinger 27m
        There has been a lot of interest in recent times in systems with non-relativistic conformal symmetry, such as the Schroedinger symmetry. Such systems appear in condensed matter physics such as, for example, fermions at unitarity. Here we discuss how to set up holography for bulk systems with Schroedinger symmetry.
        Speaker: Prof. Kostas Skenderis (University of Amsterdam)
        Slides
      • 16:45
        Towards a novel description of flavor dynamics in holographic QCD 18m
        D-branes with a U-shaped geometry, like the D8 flavor branes in the Sakai-Sugimoto model of QCD, are encountered frequently in holographic backgrounds. We argue that the commonly used DBI action is inadequate as an effective field theory description of these branes, and discuss an effective action that incorporates naturally the non-local physics of a complex scalar mode. Our results are relevant for the holographic description of chiral symmetry breaking and bare quark mass in QCD and open string tachyon condensation in curved backgrounds.
        Speaker: Dr. Vasilis Niarchos (University of Crete and Ecole Polytechnique)
        Slides
      • 17:06
        Recent progress in the AdS_4/CFT_3 correspondence 18m
        I will summarize recent progress in constructing M-theory/string theory duals to (2+1)-dimensional superconformal field theories.
        Speaker: Dr. James Sparks (University of Oxford)
        Slides
      • 17:27
        Virtual Compton Scattering off a Spinless Target in the AdS/QCD correspondence 14m
        We study the doubly virtual Compton scattering off a spinless target gamma* P -> gamma* P' within the Anti-de Sitter(AdS)/QCD formalism. We find that the general structure allowed by the Lorentz invariance and gauge invariance of the Compton amplitude is not easily reproduced with the standard recipes of the AdS/QCD correspondence. In the soft-photon regime, where the semi-classical approximation is supposed to apply best, we show that the measurements of the electric and magnetic polarizabilities of a target like the charged pion in real Compton scattering, can already serve as stringent tests.
        Speaker: Dr. Samuel Wallon (CNRS/LPT Orsay)
        Slides
      • 17:43
        Planck Scale Cosmology and Asymptotic Safety in Resummed Quantum Gravity 14m
        In Weinberg’s asymptotic safety approach to quantum gravity, one has a finite dimensional critical surface for a UV stable fixed point to generate a theory of quantum gravity with a finite number of physical parameters. The task is to demonstrate how this fixed point behavior actually arises. We argue that, in a recently formulated extension of Feynman’s original formulation of the theory, which we have called resummed quantum gravity, we recover this fixed-point UV behavior from an exact re-arrangement of the respective perturbative series. We argue that the results we obtain are consistent both with the exact field space Wilsonian renormalization group results of Reuter and Bonanno and with recent Hopf-algebraic Dyson-Schwinger renormalization theory results of Kreimer. We calculate the first "first principles" predictions of the respective dimensionless gravitational and cosmological constants and argue that they support the Planck scale cosmology advocated by Bonanno and Reuter as well. Comments on the prospects for actually predicting the currently observed value of the cosmological constant are also given.
        Speaker: Bennie Ward (Baylor University, Waco, TX, USA)
        Slides
    • 18:15 19:00
      Poster Session Opening 45m
    • 19:00 21:00
      Welcome Reception 2h
    • 09:00 10:30
      01 - Early Experience and Results from LHC Salle 251 ()

      Salle 251

      Convener: Andreas Hoecker (CERN)
      • 09:00
        First Data from the TOTEM experiment at LHC 13m
        Totem is the only LHC experiment that will explore the forward region at pseudorapidity larger than 3.1. The main goal is the measurement of the total and elastic cross-section at 14 TeV and the study of diffractive physics in the forward region. The experiment approved and funded in the 2006, was build, largely commissioned and started his data taking in December 2009. The total cross section beyond 1 TeV/c will be measured with the unprecedent precision of 1% using the luminosity independent method based on the simultaneous detection of elastic scattering at low momentum transfer and of the inelastic interactions. Protons scattered at very small angles in elastic or quasi-elastic reactions will be measured in telescopes of silicon detectors enclosed in Roman Pots, placed on both sides of the intersection regions. Inelastically produced secondaries will be measured by a forward inelastic detector covering the region 3<η<7 with full azimutal acceptance. This last detector will measure the overall rate of inelastic reactions. The TOTEM physics program also include for the first time the measurement of the charged multiplicity at the TEV scale important for the understanding of the cosmic ray events. TOTEM will take data under all LHC beam conditions including standard high luminosity runs to maximize its physics goals. This contribution describes the status of the TOTEM experiment. A first set of data at 0.9 and 2.36 TeV was recently collected and some preliminary results will be shown. In addition we will discuss the measurements to be made in the 2010 LHC runs.
        Speaker: Francesco Cafagna (Univ. + INFN)
        Slides
      • 09:15
        Early Physics with the LHCf detector at LHC 13m
        The LHCf detector is the smallest of the six experiments which are taking data at the CERN LHC accelerator. The whole detector has been installed at the beginning of 2008 on both sides of LHC collision point 1 (IP1). LHCf has been designed to measure with high accuracy energy and transverse momentum spectra of neutral particles in the very forward region (η > 8.4) of LHC collisions by means of a double arm calorimeter. Thanks to the excellent energy and position resolution of the two sampling calorimeters, LHCf is able to measure the pion production cross section through the measurement of the photons produced in the neutral pion decays. It is also able to identify neutrons and measure their energy spectrum. LHCf data provide a fundamental tool to calibrate the most widely adopted shower models used to estimate the primary energy of Ultra High Energy Cosmic Rays. Many of the experimental procedures used to derive the properties of primary UHECRs depend strongly on the nuclear interaction model used in the Monte Carlo codes of the air showers and several open questions in cosmic ray physics may profit from the accurate knowledge and calibration of Monte Carlo models provided by the LHCf experiment. LHCf experiment sucessfully took data during 2009 run at 900 GeV and it is now smoothly taking data at 7 TeV collisions. Preliminary results of the ongoing analysis will be presented.
        Speaker: Alessia Tricomi (Dipartimento di Fisica)
        Slides
      • 09:30
        First Physics Results from ALICE 25m
        ALICE is the LHC experiment dedicated to the study of heavy-ion collisions. The main purpose of ALICE is to investigate the properties of a state of deconfined nuclear matter, the Quark Gluon Plasma. Heavy flavour measurements will play a crucial role in this investigation. The physics programme of ALICE has started by studying proton-proton collisions at unprecedented high energies. We will present the first results on open heavy flavour and quarkonia in proton-proton collisions at √s = 7 TeV measured by the ALICE experiment at both mid- and forward-rapidities. We will conclude with the prospects for heavy flavour and quarkonium measurements in both proton-proton and nucleus-nucleus collisions. Also presented are first results of neutral meson reconstruction and its perspectives, as well as further physics studies.
        Speaker: Iouri BELIKOV (IPHC, CNRS-IN2P3)
        Slides
      • 10:00
        First Physics Results from LHCb 25m
        The LHCb experiment is primarily designed to study charm and bottom hadron decays at the LHC. The first exclusively reconstructed charm and bottom hadrons signals have been observed shortly after the start of the first LHC physics run at √s = 7 TeV, in events collected with a minimum bias trigger. Charm cross-sections for D0, D+, Ds and Lambda_c are measured in the forward region covered by LHCb (2 < eta < 5). We also use the semi-inclusive decay B -> D0 lep nu to ascertain the b anti-b production cross section. Preliminary results will be shown. Also reported are studies of W and Z boson, as well as low mass Drell-Yan production.
        Speaker: Sheldon STONE (Syracuse)
        Slides
    • 09:00 10:30
      02 - The Standard Model and Electroweak Symmetry Breaking Salle Maillot ()

      Salle Maillot

      Convener: Sally Dawson (BNL)
      • 09:00
        Precision Predictions for Higgs and Top-Quark Pair Production at Hadron Colliders 18m
        Precision Predictions for Top-Quark Pair Production at Hadron Colliders Content Precision predictions for phenomenologically interesting observables such as the t-tbar invariant mass distribution and forward-backward asymmetry in top-quark pair production at hadron colliders require control over the differential cross section in perturbative QCD. We improve existing calculations of the doubly differential cross section in the invariant mass and scattering angle by using techniques from soft-collinear effective theory to perform an NNLL resummation of threshold logarithms, which become large when the invariant mass M of the top-quark pair approaches the partonic center-of-mass energy sqrt(s hat). We match our results in the threshold region with the exact results at NLO in fixed-order perturbation theory, and perform a numerical analysis of the invariant mass distribution, the total cross section, and the forward-backward asymmetry. Using MSTW2008NNLO parton distribution functions (PDFs), we obtain for the inclusive production cross sections at the Tevatron and LHC the values sigma_{t tbar} = (6.30 +-0.19 -0.23+0.31) pb at the Tevatron and sigma_{t tbar} = (149 +-7 +-8) pb at the LHC, where the first error results from scale variations while the second reflects PDF uncertainties. Precision Predictions for Higgs Production at Hadron Colliders Content We use renormalization-group methods in effective field theory to improve the theoretical prediction for the cross section for Higgs-boson production at hadron colliders. In addition to soft-gluon resummation at N^3LL, we also resum enhanced contributions of the form (C_A x pi x alpha_s)^n, which arise in the analytic continuation of the gluon form factor to time-like momentum transfer. This resummation is achieved by evaluating the matching corrections arising at the Higgs-boson mass scale at a time-like renormalization point mu^2<0, followed by renormalization-group evolution to mu^2>0. We match our resummed result to NNLO fixed-order perturbation theory and give numerical predictions for the total production cross section as a function of the Higgs-boson mass. Resummation effects are significant even at NNLO, where our improved predictions for the cross sections at the Tevatron and the LHC exceed the fixed-order predictions by about 13% and 8%, respectively, for m_H=120 GeV. We also discuss the application of our technique to other time-like processes such as Drell-Yan production, e+ e- → hadrons, and hadronic decays of the Higgs boson.
        Speaker: Matthias Neubert (Mainz University)
        Slides
        Video
      • 09:20
        Studies of top quark properties at the DZero experiment 22m
        Studies of top quark properties, including spin correlations, W boson helicity, forward backward asymmetry, Wtb coupling as well as search for anomalous top quark couplings with the D0 detector will be presented.
        Speaker: Mr. Viatcheslav Sharyy (CEA-Saclay)
        Slides
        Video
      • 09:45
        Studies of top quark properties at CDF 22m
        Studies of top quark properties, including spin correlations, W polarization and forward backward asymmetry at the Tevatron's CDF detector will be presented as well as results of searches for light Higgs boson in top quark decays.
        Speaker: Andrew Eppig (University of Michigan)
        Slides
        Video
      • 10:10
        Electroweak non-resonant corrections to e+ e- → W+ W- b bbar in the t tbar resonance region 18m
        We analyse subleading electroweak effects in the top anti-top resonance production region in e+ e- collisions which arise due to the decay of the top and anti-top quarks into the W+ W- b bbar final state. These are NLO corrections adopting the non-relativistic power counting v ~ alpha_s ~ sqrt(alpha_EW). In contrast to the QCD corrections which have been calculated (almost) up to NNNLO, the parametrically larger NLO electroweak contributions have not been completely known so far, but are mandatory for the required accuracy at a future linear collider. The missing parts of these NLO contributions arise from off-shell top production and decay and other non-resonant irreducible background processes to t tbar production. We consider the total cross section of the e+ e- → W+ W- b bbar process and additionally implement cuts on the invariant masses of the W+ b and W- bbar pairs.
        Speaker: Dr. Pedro Ruiz-Femenia (RWTH Aachen University)
        Slides
        Video
    • 09:00 10:30
      03 - Perturbative QCD, Jets and Diffractive Physics Salle 252B ()

      Salle 252B

      Convener: Gudrun Heinrich (University of Durham)
      • 09:00
        Monte Carlo tools for the LHC 25m
        The status of the standard multi-purpose Monte Carlo tools for LHC physics is reviewed, with a special emphasis on recent developments. These include the systematic inclusion of higher-order corrections and the modelling of soft QCD.
        Speaker: Frank Krauss (University of Durham)
        Slides
      • 09:30
        Multi-jet merging with NLO matrix elements 17m
        Multi-jet merging of matrix elements and parton showers in Monte-Carlo event generators has become a crucial tool for LHC predictions. An existing algorithm for tree-level matrix elements is extended to full NLO accuracy.
        Speaker: Frank Siegert (IPPP Durham and UC London)
        Slides
      • 09:50
        Monte Carlo modelling of NLO DGLAP QCD Evolution in the fully unintegrated form 17m
        We would like to present recent work, which is going to change three-decades old paradigm of perturbative QCD calculations, in which hard process matrix element calculated to LO+NLO(+NNLO) level is combined with: either the collinear PDF at LO+NLO(+NNLO) or with the Monte Carlo parton shower, but the MC PS restricted to LO only! For many years upgrading Monte Carlo parton shower to NLO level was regarded as unfeasible in practice or in principle, or both. In a series of the recent works we demonstrate that for NLO non-siglet subset of diagrams we are able to implement in the Monte Carlo PS the exact DGLAP evolution, without any approximation. This seminal work, after extending to complete NLO DGLAP, will lead to a new class of powerful techniques of combining resummed and finite order pQCD calculations in a form of Monte Carlo event generators for W/Z production at hadron collider experiments.
        Speaker: Aleksander Kusina (Institute of Nuclear Physics PAN)
        Slides
      • 10:10
        HERWIRI1.031: New Approach to Parton Shower MC's in Precision QCD Theory 17m
        By implementing the new IR-improved Dokshitzer-Gribov-Lipatov-Altarelli-Parisi-Callan-Symanzik (DGLAP-CS) kernels recently developed by one of us in the HERWIG6.5 environment we generate a new MC, HERWIRI1.0(31), for hadron-hadron scattering at high energies. We use MC data to illustrate the comparison between the parton shower generated by the standard DGLAP-CS kernels and that generated by the new IR-improved DGLAP-CS kernels. The interface to MC@NLO, MC@NLO/HERWIRI, is illustrated. Comparisons with FNAL data and some discussion of possible implications for LHC phenomenology are also presented.
        Speaker: Prof. Bennie Ward (Baylor University)
        Slides
    • 09:00 10:30
      04 - Hadronic Structure, Parton Distributions, soft QCD, Spectroscopy Salle 253 ()

      Salle 253

      Convener: Enrico Tassi (Dipartimento di Fisica-Univ. degli Studi della Calabria)
      • 09:00
        Charged Particle Distributions in Deep Inelastic Scattering and Photoproduction 13m
        Transverse Momentum of Charged Particles at low Q^2 at HERA 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. Scaled momentum distributions of charged particles in dijet photoproduction at HERA The scaled momentum distributions of charged particles in jets have been measured for dijet photoproduction with the ZEUS detector at HERA using an integrated luminosity of 359 pb-1. The distributions are compared to predictions based on perturbative QCD carried out in the framework of the modified leading-logarithmic approximation (MLLA) and assuming local parton-hadron duality (LPHD). The universal MLLA scale, Lambda_eff, and the LPHD parameter, kappa^ch, are extracted. Scaled Momentum Spectra in deep inelastic Scattering at HERA Charged particle production has been studied in neutral current deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 0.44 fb-1. Distributions of scaled momenta in the Breit frame are presented for particles in the current fragmentation region. The evolution of these spectra with the photon virtuality, Q2, is described in the kinematic region 10 < Q2 < 41000 GeV2. Next-to-leading-order and modified leading-log- approximation QCD calculations as well as predictions from Monte Carlo models are compared to the data. The results are also compared to e+e- annihilation data. The dependences of the pseudorapidity distribution of the particles on Q2 and on the energy in the p system, W, are presented and interpreted in the context of the hypothesis of limiting fragmentation.
        Speaker: Daniel Traynor (Queen Mary, Univ. of London)
        Slides
      • 09:15
        Light Mesons and Strange Particle Production at HERA 13m
        Inclusive Photoproduction of rho^0, K^{*0} and phi Mesons at HERA Inclusive non-diffractive photoproduction of rho(770)^0, K^*(892)^0 and phi(1020) mesons is investigated with the H1 detector in ep collisions at HERA. The corresponding average gamma p centre-of-mass energy is 210 GeV. The mesons are measured in the transverse momentum range 0.5 < p_T < 7 GeV and the rapidity range |y_{lab}|<1. Differential cross sections are presented as a function of transverse momentum and rapidity, and are compared to the predictions of hadroproduction models. Strangeness Production at low Q^2 in Deep-Inelastic ep Scattering at HERA The production of neutral strange hadrons is investigated using deep-inelastic scattering events measured with the H1 detector at HERA. The measurements are made in the phase space defined by the negative four-momentum transfer squared of the photon 2 < Q^2 < 100 GeV^2 and the inelasticity 0.1 < y < 0.6. The K0_s and Lambda production cross sections and their ratios are determined. K0_s production is compared to the production of charged particles in the same region of phase space. The Lambda- anti-Lambda asymmetry is also measured and found to be consistent with zero. Predictions of leading order Monte Carlo programs are compared to the data. K0_s Production at high Q^2 at HERA The production of K0_s mesons is studied at high Q^2, using DIS events recorded with the H1 Detector. Using the full HERA-2 statistics, the production cross sections of K0_s are presented, differentially as a function of several kinematical variables. Moreover, the K0_s production rate is compared to the equivalent 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. Scaled momentum spectra of identified particles in the Breit frame at HERA Scaled momentum distributions of identified particles, K0S and Lambda, have been measured in deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 290 pb^-1. The evolution of these distributions with the photon virtuality, Q^2, are studied in the kinematic region 10 < Q^2 < 40000 GeV^2. The distributions have been measured in the current fragmentation region of the Breit frame. Next-to-leading-order QCD calculations including hadron-mass effects are compared to the data. The calculations reproduce the trends of the measured distributions as functions of Q^2 and the scaled momentum variable reasonably well.
        Speaker: Leszek Zawiejski (Institute of Nuclear Physics PAN)
        Slides
      • 09:30
        Charm Fragmentation and Excited Charm Meson Production at HERA 13m
        Study of Charm Fragmentation into D^{*+-} Mesons in Deep-Inelastic Scattering at HERA The process of charm quark fragmentation is studied using D^{*+-} meson production in deep-inelastic scattering as measured by the H1 detector at HERA. Two different regions of phase space are investigated defined by the presence or absence of a jet containing the D^{*+-} meson in the event. The parameters of fragmentation functions are extracted for QCD models based on leading order matrix elements and DGLAP or CCFM evolution of partons together with string fragmentation and particle decays. Additionally, they are determined for a next-to-leading order QCD calculation in the fixed flavour number scheme using the independent fragmentation of charm quarks to D^{*+-} mesons. Measurement of the charm fragmentation function in D* photoproduction at HERA The charm fragmentation function has been measured in D* photoproduction with the ZEUS detector at HERA using an integrated luminosity of 120 pb-1. The fragmentation function is measured versus z, the ratio of E+p_parallel for the D* meson and that for the associated jet, where E is the energy and p_parallel the longitudinal momentum relative to the jet axis. Jets were reconstructed using the k_T clustering algorithm and required to have transverse energy greater than 9 GeV. The D* meson associated with the jet was required to have a transverse momentum greater than 2 GeV. The measured function is compared to different fragmentation models incorporated in leading-logarithm Monte Carlo simulations and a next-to-leading-order calculation. The results are similar to those from e+e- experiments. Excited charm meson production at HERA The production of the excited charm mesons D1(2420)0 and D2*(2460)0 in inelastic ep scattering was studied with the ZEUS detector at HERA using an integrated luminosity of 372 pb-1. Masses and widths were determined and and a helicity analysis was performed. The results are compared with previous measurements and with theoretical expectations.
        Speaker: Olaf Behnke (DESY)
        Slides
      • 09:45
        Particle Production Studies at LHCb 13m
        Prompt K0_s production in pp collisions at the LHCb experiment The inclusive production of prompt K0_s mesons, which are either produced directly in the fragmentation process or in the decay chain of prompt resonances decaying strongly or electromagnetically, has been studied with the very first data collected in pp collisions at sqrt(s) = 0.9 TeV using the LHCb detector in December 2009. K0_s decays are identified kinematically using the information recorded by the LHCb tracking detectors, in events passing a minimum bias trigger. The absolute differential production cross section is measured as a function of the K0_s transverse-momentum (pT ) and rapidity y in the region 0.2 < pT < 1.6 GeV/c and 2.5 < y < 4.0. The pT spectra, which are a sensitive probe of the hadronization mechanism, are compared with predictions from specific tunings of the PYTHIA generator. Preliminary results obtained at sqrt(s) = 7 TeV may be shown as well. Baryon/anti-baryon production studies at LHCb Baryon number and strangeness can be used to probe the fragmentation field. Predictions for the inclusive production of baryons and anti-baryons at LHC energies differ significantly between models tuned on the same lower-energy data, especially at large pseudo-rapidities (eta). The LHCb experiment, with its forward coverage (2 < eta < 5), is in a unique position at LHC to study how well the quantum numbers of the beam particles are transported to the central region. Preliminary results on the inclusive production of protons and anti-protons, as well as Lambda and anti-Lambda hyperons, will be presented, with a specific emphasis on the baryon/anti-baryon production ratios as a function of rapidity, transverse momentum, and center-of-mass energy. Measurement will be compared with predictions from Monte Carlo generators tuned on experimental results. First studies with J/psi signals at LHCb An important part of the LHCb physics programme relies on the ability to efficiently trigger and cleanly reconstruct J/psi -> μ+μ− decays. The first heavy flavour measurement at LHCb will concern J/psi production, and open the road for further quarkonium and B physics studies. Experience on the triggering and reconstruction of J/psi decays acquired by LHCb during the initial phase of the LHC startup at sqrt(s) = 7 TeV will be reported. Contributions of J/psi from b-hadron decays will be separated from prompt J/psi produced directly in the pp collisions or in the decays of heavier prompt states. Preliminary results on the prompt and non-prompt J/psi production cross section will be presented as a function of the J/ transverse-momentum (pT ) and rapidity (y) in the range 3 < y < 5 and pT < 7 GeV/c.
        Speaker: Chris Blanks (Imperial College)
        Slides
      • 10:00
        Recent STAR results and future prospects of W^-(+) boson production in polarized p+p collisions at RHIC 13m
        The RHIC spin physics program has in 2009 completed the first data taking period of polarized p+p collisions at sqrt{s}=500 GeV. This opens a new era in the study of the spin-flavor structure of the proton based on the production of W^-(+) bosons. W^-(+) bosons are produced in ubar+d,(dbar+u) collisions and can be detected through their leptonic decays, e^- + νbar_e;(e^+ +ν_e), where only the respective charged lepton is measured. The discrimination of ubar+d and dbar+u quark combinations requires distinguishing the charge sign of high p_T electrons and positrons, which in turn requires precise tracking information. At mid rapidity, STAR relies on the existing Time Projection Chamber. At forward rapidity, new tracking capabilities will be provided by the Forward GEM Tracker, consisting of six triple-GEM detectors which are under construction. The suppression of QCD background over W boson signal events by several orders of magnitude is accomplished by using the highly segmented STAR Electromagnetic Calorimeters to impose isolation criteria suppressing jet events, and vetoing di-jet events based on the measured away side energy. Recent STAR results on the first measurement of W^-(+) boson production in polarized p+p collisions will be shown along with a discussion of future prospects involving the STAR Forward GEM Tracker.
        Speaker: Prof. Bernd The STAR Collaboration (MIT)
        Slides
      • 10:15
        Parity violating single spin asymmetry in W production from longitudinally polarized p+p collisions at 500 GeV 13m
        Electrons from W^± decays have been observed in longitudinally polarized p+p collisions at sqrt{s} = 500 GeV in the PHENIX detector at RHIC. The electron energy spectrum from W decays measured with an integrated luminosity of approximately 10 pb^-1 will be shown. A measurement of the electron single spin asymmetry which measures the spin structure of flavor identified quarks and antiquarks in the proton will be reported.
        Speaker: Dr. John The PHENIX Collaboration (Brookhaven National Laboratory)
        Slides
    • 09:00 10:30
      06 - CP violation, CKM and Rare Decays Salle 242A ()

      Salle 242A

      Convener: Francesca Di Lodovico (Queen Mary University of London)
      • 09:00
        The new KL->pi0nunu Experiment (KOTO) at J-PARC 13m
        J-PARC-E14 KOTO experiment aims at first observation of the rare decay KL->pi0nunu using an intense KL beam in the Hadron experimental hall at J-PARC. The new dedicated KL beamline for KOTO experiment has been constructed in 2009. First KL beam was successfully extracted and surveyed from Oct. in 2009 to Feb. in 2010. Assembling of main detector part, which is composed of 2716 CsI crystals, was just started in May, 2010. Whole detector system will be completed in 2011 and total engineering run and first physics run will be started. In this contribution, the preparation status of the beamline and the detector will be reported.
        Speaker: Dr. Hiroaki Watanabe (KEK)
        Slides
      • 09:15
        Measurement of BR(K -> e nu)/BR(K -> mu nu) at NA62 13m
        Measurement of the helicity suppressed ratio of charged kaon leptonic decay rates BR(K -> e nu)/BR(K -> mu nu) has long been considered as an excellent test of lepton universality and the Standard Model (SM) description of weak interactions. It was realised recently that the suppression of the SM contribution might enhance the sensitivity to SUSY-induced effects to an experimentally accessible level. The NA62 experiment at the CERN SPS has collected a record number of over 10^5 K -> e nu decays during a dedicated run in 2007, aiming at achieving 0.5% precision. Experimental strategy, details of the analysis and preliminary results will be discussed.
        Speaker: Andreas Winhart (Institut fur Physik)
        Slides
      • 09:30
        Analysis of the MEG experiment to search for mu+ -> e+ gamma decays 13m
        A lepton flavor violating rare muon decay mu -> e gamma is forbidden in the standard model. On the other hand, new theories, such as supersymmetric grand-unification theory etc, predict the branching ratio in the range of 10^{-14}-10^{-12}, which is just below the current experimental upper bound (1.2x10^{-11}) set by a previous experiment. MEG experiment is designed to search for the decay with a sensitivity of 10^{-13}. The physics run was started in 2008. Sensitivity from the initial three months of data is 1.3x10^{-13}, and 90% confidence level limit was set to be 2.8x10^{-11}. In 2009, more than twice the data with respect to 2008 was acquired, hence it is promising the sensitivity will be better than the current limit. In this talk, details of analyses of each sub-detectors (900 litter liquid xenon calorimeter, ultra-light drift chambers and high resolution timing counters) and physics analysis for 2009 data are described.
        Speaker: Dr. Ryu Sawada (The University of Tokyo)
        Slides
      • 09:45
        Search for lepton flavour violating tau decay and lepton-number violation B decay at Belle 13m
        We present the results of a search for lepton flavor violation (LFV) in tau --> lepton (e or mu) + pseudoscalar (pi0, eta or eta') and in tau --> lepton (e or mu) + a vector meson (rho, omega, phi, K^{*0}, anti-{K}^{*0}) decays using a large data sample accumulated with the Belle detector at the KEKB symmetric-energy e^+e^- collider. The sensitivity to these modes is significantly improved compared to previous experiments. In the Standard Model, lepton-number-violating decays such as B^+ --> D^- l^+ l^+ are strictly forbidden, but they are allowed if Majorana-type neutrinos exist. We present the results of a search for B^+ --> D^- l^+ l^+ decays with a high-statistics B anti-{B} event sample.
        Speaker: Kiyoshi Hayasaka (Nagoya Univ.)
        Slides
      • 10:00
        Tau lifetime and CP violation in tau decay at Belle 13m
        The tau lepton lifetime is measured using the process e^+ e^- --> tau^+ tau^-, where both tau leptons decay to 3 pi nu. An upper limit on the relative lifetime difference between positive and negative tau-leptons is given. The obtained results are based on a large data sample collected on the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We also present the results of a search for CP violation in tau --> nu K_S pi. CP violation in semileptonic tau decays is generally forbidden in the Standard Model but can be induced by the exchange of an exotic scalar such as a charged Higgs in supersymmetric models. Exploiting the large statistics of the Belle data set, we report a model-independent limit for CP violation as well as a significantly improved measurement of the CP violation parameters for specific parameterizations of the hadronic structure functions.
        Speaker: Mikhail Shapkin (IHEP)
        Slides
      • 10:15
        Measurements of |Vus| and Second Class Currents and Searches for Violation of Lepton Universality and CPT in Tau Decays at BABAR 13m
        We report on a variety of results involving decays of the tau lepton using the very large sample of tau+tau- pairs produced in e+e- annihilation data collected with the BaBar detector at the PEP-II asymmetric-energy B Factory near a center-of-mass energy of 10.58 GeV. From measurements of the ratios of branching fractions: B(tau -> mu nu nubar) / B(tau -> e nu nubar), B(tau -> pi nu) / B(tau -> e nu nubar), and B(tau -> K nu) / B(tau -> e nu nubar) we test with high precision the Standard Model assumption of mu-e and tau-mu charged current lepton universality and provide a determination of the Cabibbo-Kobayashi-Maskawa matrix element |V_{us}|. Furthermore, we report on preliminary measurements of tau^- --> K^- n pi^0 nu{tau} with n = 0,1,2,3 and tau^- --> pi^- n pi^0 nu_{tau} with n = 3,4 as well as on the measurements of the branching fractions and hadronic mass distributions of tau- -> KS0 pi- nu_tau, tau -> KS0 pi- pi0 nu_tau, tau -> KS0 pi- K0L nu_tau. Data from the inclusive strange tau decay results are used in a different determination of |V_{us}|. We also report on our search for second class currents in tau-- > pi- eta nu_tau, where the eta decays into pi+pi-pi0 and our measurement of the tau mass. We obtain a test of CPT by measuring the difference between the masses of the tau+ and tau-.
        Speaker: Alberto Lusiani (Dipartimento di Fisica)
        Slides
    • 09:00 10:30
      09 - Progress in Lattice Techniques and New Results Salle 252A ()

      Salle 252A

      Convener: Prof. Pilar Hernandez (University of Valencia)
      • 09:00
        Light quarks on the lattice: methods and results for pion physics 35m
        Ab-initio studies of the physics of pions using lattice QCD have become possible over the last decade, where particular attention was given to the computation of the constants of the chiral Lagrangian. This is due to significant progress in algorithms, which now allow simulations with light sea quarks on fine lattices. This talk has two objectives: the first is to introduce the ideas behind the algorithmic advances along with the status and prospects of the simulations. After that, the state of the physics results will be reviewed, with particular emphasis on the chiral low-energy constants.
        Speaker: Stefan Schaefer (Humboldt University Berlin)
        Slides
      • 09:35
        Lattice studies of hadron physics with disconnected quark loops 25m
        Disconnected diagrams give crucial contributions to the physics of flavor singlet hadrons and to scalar form factors of non-singlet hadrons. Lattice calculation of the disconnected diagrams is not straightforward because naively it requires huge number of fermion matrix inversions. In this talk, we present recent progress with improved simulation methods particularly focusing on the flavor-singlet meson spectrum and nucleon strange quark content.
        Speaker: Takashi Kaneko (KEK)
        Slides
      • 10:00
        Leading order hadronic contribution to g-2 from lattice QCD 30m
        The nonperturbative calculation of the hadronic contributions to the anomalous magnetic moment of the muon is an interesting challenge for QCD, especially in light of the continuing discrepancy between the Standard Model prediction and experimental measurements. We have calculated the leading order hadronic contribution using lattice QCD with pion masses ranging from 600 MeV down to 300 MeV. The systematic errors in such a calculation have been studied with calculations at two lattice spacings and several volumes.
        Speaker: Dr. Dru Renner (DESY, Zeuthen)
        Slides
    • 09:00 10:30
      10 - Beyond the Standard Model (theory and experimental searches) Salle 242B ()

      Salle 242B

      Convener: Sacha Davidson (Institut de Physique Nucleaire de Lyon (IPNL)-Universite Claude Bernard)
      • 09:00
        A Review of the Mass Measurement Techniques proposed for the Large Hadron Collider 20m
        We review the methods which have been proposed for measuring masses of new particles at the Large Hadron Collider paying particular attention to the kinematical techniques suitable for extracting mass information when invisible particles are expected. This talk is, in effect, a companion to a recent review with the same title: http://arxiv.org/abs/1004.2732 (Barr & Lester)
        Speaker: Dr. Christopher Gorham Lester (University of Cambridge)
        Slides
      • 09:25
        Early LHC data preparations for beyond-the-standard-model searches at CMS 15m
        Searches for supersymmetry (SUSY) and other phenomena beyond the standard model involve a broad range of signatures with jets, leptons, photons, and missing transverse momentum (MET). These searches require careful control over backgrounds from standard model processes. We present the current understanding of these issues both in SUSY searches and in other beyond-the-standard-model searches such as first and second generation leptoquarks. We present several methods for data-driven background determinations that have been tested on early LHC data collected by the CMS experiment at sqrt(s)=7 TeV. These data allow us to study QCD backgrounds, to evaluate methods to suppress the effects of jet-energy mis-measurement, to validate data-driven methods for predicting the MET distribution, and to measure background contributions from processes producing fake leptons.
        Speaker: Didar Dobur (University of Florida)
      • 09:45
        Z' discovery potential at the LHC in the minimal B-L model 15m
        We present the Large Hadron Collider (LHC) discovery potential in the Z' sector of a U(1)_{B-L} enlarged Standard Model (that also includes three heavy Majorana neutrinos and an additional Higgs boson) for sqrt{s}=7 and 14 TeV centre-of-mass (CM) energies, considering both the Z'_{B-L} -> e+e- and Z'_{B-L} -> µ+µ- decay channels. The run of the LHC at sqrt{s}=7 TeV, assuming at most ∫L ~ 1 fb-1, will be able to give similar results to those that will be available soon at the Tevatron in the lower mass region, and to extend them for a heavier M_{Z'}. Finally, the run at 14 TeV is needed to fully probe the parameter space and its potential is comparable in scope to that of a future TeV scale Linear Collider (LC). If no evidence is found in any energy configuration, 95% C.L. limits can be determined, and, given their better resolution, the limits from electrons will always be more stringent than those from muons.
        Speaker: Lorenzo Basso (Rutherford Appleton Laboratory - STFC)
        Slides
      • 10:05
        Early Searches with Leptons and Photons with the ATLAS Detector at the LHC 15m
        The Standard Model predicts relatively low backgrounds to processes with high-pt leptons, and photons making them strong candidates for early discoveries. We present the results of the most sensitive such searches based on first data collected with the ATLAS detector at the LHC.
        Speaker: Dr. Dominique Fortin (TRIUMF)
        Slides
    • 10:30 11:00
      Coffee Break 30m
    • 11:00 12:30
      01 - Early Experience and Results from LHC Salle 251 ()

      Salle 251

      Convener: Andreas Hoecker (CERN)
      • 11:00
        First Results from ATLAS on QCD, Quarkonia, and Heavy-Flavour Physics in proton-proton Collisions at √s=7 TeV 20m
        This talk will give an overview on first results on QCD, quarkonia, and heavy-flavour physics in proton-proton collisions at √s=7 TeV, recorded with the ATLAS experiment at the LHC. The QCD measurements address properties of both soft and hard collisions, such as the underlying event, particle production in minimum bias events and jet production. First results from quarkonia and heavy flavour production will be highlighted.
        Speaker: Julie Kirk (RAL)
        Slides
      • 11:25
        First Results from CMS on QCD, Quarkonia, and Heavy-Flavour Physics in proton-proton Collisions at √s=7 TeV 20m
        This talk will give an overview on first results on QCD, quarkonia, and heavy-flavour physics in proton-proton collisions at √s=7 TeV, recorded with the CMS experiment at the LHC. The QCD measurements address properties of both soft and hard collisions, such as the underlying event, particle production in minimum bias events and jet production. First results from quarkonia and heavy flavour production will be highlighted.
        Speaker: Sara Bolognesi (CERN)
        Slides
      • 11:50
        W and Z boson production at CMS in pp collisions at √s=7 TeV 15m
        The production of W and Z bosons has been observed in pp collisions at a center-of-mass energy of 7 TeV using data collected in the CMS experiment. W events were selected containing an isolated, energetic electron or muon. The presence of an energetic neutrino is demonstrated using the distribution of missing transverse energy (MET), which is calculated from calorimetric and tracking information in three ways. 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 √s=7 TeV, as well as preliminary distributions of kinematic variables. Emphasis is put on the weak boson reconstruction performance.
        Speaker: Maria Cepeda (CIEMAT (Madrid))
        Slides
      • 12:10
        First Results from ATLAS on W and Z Boson Production in proton-proton Collisions at √s=7 TeV 15m
        This talk will give an overview on first results on W and Z production in proton-proton collisions at √s=7 TeV, recorded with the ATLAS experiment at the LHC. The selection of W and Z events will be described, together with data-driven methods used to estimate the trigger and reconstruction efficiencies, as well as the main backgrounds. The W and Z signal yields and the extracted cross sections at √s=7 TeV will be presented, as well as preliminary distributions of kinematic variables and first measurements of the W charge and polarization asymmetry.
        Speaker: Dr. Jan Kretzschmar (University of Liverpool)
        Slides
    • 11:00 12:30
      02 - The Standard Model and Electroweak Symmetry Breaking Salle Maillot ()

      Salle Maillot

      Convener: Maarten Boonekamp (DAPNIA)
      • 11:00
        Precision measurement of the top quark mass and width with the DZero detector 22m
        We report a set of measurements of the top quark mass obtained from proton-antiproton collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron with the DZero detector using different decay modes and analysis methods. We present measurements of the top quark width, and mass difference between the top and anti-top quark as well.
        Speaker: Alexander Grohsjean (Ludwig-Maximilians-Univ. Muenchen)
        Slides
        Video
      • 11:25
        Measurement of the top quark mass and width with CDF detector 22m
        We report a measurement of the top quark mass obtained from proton-antiproton collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron using the CDF II detector using different decay modes and analysis methods. We present measurements of the top quark width, and mass difference between the top and anti-top quark in the lepton+jets channel as well.
        Speaker: Hyunsu Lee (University of Chicago)
        Slides
        Video
      • 11:50
        Top quark study at CMS 18m
        The top quark is a fundamental building block of the standard model. Due to the large cross section, top-antitop pairs will be copiously produced in high energy proton-proton collisions at the Large Hadron Collider (LHC). We present the first results of a selection of top-quark pair production events in the dilepton channel, where both W-bosons from the top quarks decay leptonically into either an electron or a muon, plus a neutrino. We use LHC collision data at 7 TeV centre-of-mass energy collected with the CMS experiment during the period of April to July 2010. Events with two isolated, prompt leptons with high energy, at least two jets with high transverse momentum, and significant missing transverse energy are selected. Several background contributions from other standard model processes, most importantly Drell-Yan and W+jets, are estimated in a data-driven way. Results obtained from data are compared with the simulation, indicating the status of the analysis towards a first cross section measurement in this channel at sqrt(s) = 7 TeV. Similarly, first results are reported for the lepton+jets channel, where one W-boson from the top decays leptonically into a muon (or electron) and a neutrino, while the other one decays into a quark-antiquark pair.
        Speaker: Tim Christiansen (CERN)
        Slides
        Video
      • 12:10
        Top quark studies with ATLAS 18m
        First results from the ATLAS experiment at the LHC at center of mass energy of 7 TeV on top quark studies will be presented. In addition prospects on top quark studies at ATLAS including the top quark mass, top quark decay properties, spin correlations and anomalous couplings, rare decays and single top quark production will be discussed.
        Speaker: Arnaud Lucotte (LPSC Laboratoire de Physique Subatomique et de Cosmologie (LPSC))
        Slides
        Video
    • 11:00 12:30
      03 - Perturbative QCD, Jets and Diffractive Physics Salle 252B ()

      Salle 252B

      Convener: Leszek Motyka (Hamburg University)
      • 11:00
        Probing the theoretical description of central exclusive production 17m
        We investigate the theoretical description of the central exclusive production process. Taking Higgs production as an example, we sum logarithmically enhanced corrections appearing in the perturbation series to all orders in the strong coupling. In addition, we perform a fixed order calculation of the corrections relevant for the Sudakov factor appearing in the process. Both approaches agree with those originally presented by Khoze, Martin and Ryskin, except that the scale, µ, appearing in the Sudakov factor must be changed from µ = 0.62 sqrt(s) to µ = sqrt(s), where s is the invariant mass squared of the central system. We discuss the effects of this modification on predictions for the LHC and the Tevatron.
        Speaker: Dr. tim coughlin (university college london)
        Slides
      • 11:20
        Exclusive Processes at HERA 25m
        Diffractive cross sections of electroproduction of rho and phi mesons is measured at HERA with the H1 detector in the elastic and proton dissociative channels. The data correspond to an integrated luminosity of 51 pb^-1. Based on data collected with the H1 detector at HERA in 2005, cross sections or elastic rho photoproduction have been measured at momentum transfer |t| < 0.58 GeV^2 and photon-proton center-of-mass energies 20 < W < 90 GeV. This data has been combined with cross sections published previously by the Omega and ZEUS collaborations in a global fit to determine the pomeron trajectory alpha(t) in 13 bins of t by from the W-dependence of the elastic rho production cross section. Exclusive diffractive photoproduction of J/psi mesons is measured with the H1 detector at the electron-proton collider HERA. At the end of the HERA operation in 2007 the nominal proton beam energy was reduced from 920 GeV to 575 and 460 GeV, respectively. The reduced proton beam energy allows diffractive J/psi measurements in an extended phase space towards lower photon-proton centre of mass energies W_gammap. Differential cross sections are presented as a function of t, the squared four-momentum transfer at the proton vertex, and of W_gammap in the kinematical range of low photon virtualities of Q^2 < 2.5 GeV^2. The exclusive photoproduction reaction gamma p -> Upsilon p has been studied with the ZEUS detector in ep collisions at HERA using an integrated luminosity of 468 pb-1. The measurement covers the kinematic range 60 < W < 220 GeV and Q^2 < 1 GeV^2, where W is the photon-proton centre-of-mass energy and Q^2 is the photon virtuality. The gamma-p cross section for Upsilon photoproduction is presented as a function of W and |t|, where t is negative transverse momentum square at the proton vertex. These results, which represent the analysis of the full ZEUS data sample for dimuon decay channel, are compared to predictions based on perturbative QCD. The proton-dissociative diffractive photoproduction of J/psi mesons has been studied in ep collisions with the ZEUS detector at HERA using an integrated luminosity of 112 pb. The cross section is presented as a function of the photon-proton centre-of-mass energy and of the squared four-momentum transfer at the proton vertex. The results are compared to perturbative QCD calculations. The J/Psi decay angular distributions have been measured in inelastic photoproduction in ep collisions with the ZEUS detector at HERA, using an integrated luminosity of 468 pb-1. The range in photon-proton centre-of-mass energy, W, was 50 < W < 180 GeV. The J/Psi mesons were identied through their decays into muon pairs. The polar and azimuthal angles of the muon+ were measured in the J/Psi rest frame and compared to theoretical predictions at leading and next-to-leading order in QCD.
        Speaker: Armen Bunyatyan (DESY)
        Slides
      • 11:50
        Exclusive processes beyond leading twist: gamma*T -> rhoT impact factor with twist three accuracy 17m
        We describe a consistent approach to factorization of scattering amplitudes for exclusive processes beyond the leading twist approximation. The method is based on the Taylor expansion of the scattering amplitude in the momentum space around the dominant light-cone direction and thus naturally introduces an appropriate set of non-perturbative correlators which encode effects not only of the lowest but also of the higher Fock states of the produced particle. The reduction of original set of correlators to a set of independent ones is achieved with the help of equations of motion and invariance of the scattering amplitude under rotation on the light-cone. As a concrete application, we compute the expressions of the impact factor for the transition of virtual photon to transversally polarised rho-meson up to the twist 3 accuracy. (Phys.Lett.B682:413-418,2010 and Nucl.Phys.B828:1-68,2010.)
        Speaker: Lech Szymanowski (Soltan INS, Warsaw)
        Slides
      • 12:10
        Exclusive Higgs production at the LHC 17m
        After a brief description of the models of exclusive diffractive Higgs prodution, we first evaluate the theoretical uncertainties that affect the calculation of exclusive cross section (jets, Higgs...). In addition, in view of the recent measurement of exclusive dijet at CDF and the new implementation of the corresponding cross section in FPMC (Forward Physics Monte-Carlo), we developed an analysis strategy that can be used to narrow down these uncertainties with the help of early LHC measurement.
        Speaker: Royon Christophe (DAPNIA)
        Slides
    • 11:00 12:30
      04 - Hadronic Structure, Parton Distributions, soft QCD, Spectroscopy Salle 253 ()

      Salle 253

      Convener: Barbara Pasquini (University of Pavia)
      • 11:00
        Recent Developments in Hadron Spectroscopy 18m
        In this introductory overview I will discuss recent developments in hadron spectroscopy that are of particular relevance to this meeting, including the spectroscopy of heavy quark hadrons, exotic and multiquark systems, and new theoretical results such as developments in LQCD.
        Speaker: Prof. Ted Barnes (ORNL)
        Slides
      • 11:20
        KLOE Results and Hadron Physics with KLOE-2 18m
        KLOE results on light meson spectroscopy The KLOE experiment has collected 2.5 fb-1 at the peak of the phi resonance at the e+e- collider DAPHNE in Frascati. The whole data set includes 100 million eta's produced through the radiative decay phi --> eta gamma and tagged by means of the monochromatic recoil photon. With this sample, we are studying eta rare decays. We have a final result for the BR measurement of the eta --> pi+pi-e+e- decay, with a sample of 1600 signal events, 100 times larger than today best measurement. These events are also used to measure the asymmetry between the pi+pi- and the e+e- decay planes in the eta rest frame, whose observation could test unexpected mechanism of CP violation, thus providing an hint of new physics beyond the Standard Model. The same data set has been also used to extract the BR for the never observed before eta --> e+ e- e+ e- decay channel. We have studied the dynamics of the eta --> pi0 pi0 pi0 decay using the Dalitz plot technique, obtaining a new determination of the quadratic slope. The result is consistent with the present world data and with current chiral perturbation theory calculations within the unitary approach. In the eta --> pi+ pi- gamma decay a significant contribution from chiral anomaly is expected. The distribution of the invariant mass of the pions allows to disentangle this contribution from resonant intermediate processes. Old measurements from the '70s with data samples of the order of 10^4 events provided contradicting results. KLOE data contains about 3.5 x 10^6 eta --> pi+ pi- gamma decays. With this statistics it is possible to investigate in detail the pion invariant mass distribution and to search for C violation signature in the left-right charge asymmetry. Currently we have used 1.2 fb-1 to perform a preliminary measurement of the branching ratio and to tune the analysis for the study of the pi+ pi- invariant mass. From a sample of 240 pb-1 taken off the phi resonance, a preliminary analysis of the e+ e- --> e+ e- eta process, without tagging e+e- in the final state and identified through the eta --> pi+ pi- pi0 channel, is presented. The same data set has been used to search for the f0(600) that can be produced in gamma-gamma interactions and observed in the reaction e+ e- --> e+ e- pi0 pi0. The preliminary pi0pi0 mass spectrum show an excess of events with respect to the expected background in the f0(600) mass region. From the process e+ e- --> pi+ pi- gamma it is possible to test scalar meson contribution using the interference among final state radiation, scalar and vector meson exchanges. This interference produces a forward backward asymmetry as a function of the pi+pi- invariant mass. Preliminary results are presented both for on-peak and off-peak data, showing a good agreement with MC expectations containing scalar and VMD contributions extracted from KLOE data. KLOE Measurement of sigma_pi^+pi^-(gamma) with ISR and pi-pi contribution to the muon anomaly The KLOE experiment, operating at the Frascati φ-factory DAφNE, has measured the differential cross section for the process $e^+e^- --> pi^+pi^-gamma as a function of the pi^+pi^- invariant mass, M_pi-pi, using two different configurations: (a) a non-observed photon, emitted at small angle (SA), whose energy is obtained by kinematics; (b) a photon emitted at large angle and detected in the calorimeter (LA) where its energy is measured. With the two samples the M^2_pi-pi range 0.1 < M^2_{pi-pi} < 0.95 GeV^2 is covered. The measurement of the pi^+pi^- cross section at SA, normalized to the integrated luminosity has been published recently. We present the final results of a new independent measurement at LA using data taken in 2006 at a collision energy of 1 GeV, 20 MeV below the φ-peak. We will discuss also the impact of these measurement on the evaluation of the hadronic contribution to the muon anomaly, and the results on the exctraction of the pion form factor from the ratio of sigma(e^+e^- --> pi^+pi^-gamma) to sigma(e^+e^--> mu^+mu^-\gamma). Hadron Physics with KLOE-2 Experiments at the Phi-factory can shed light on many aspects of hadron physics. A new beam crossing scheme allowing for a reduced beam size and increased luminosity is operating at DAφNE. The KLOE-2 detector is successfully rolled in this new interaction region and is ready to acquire collision data. At the moment, the detector is being upgraded with small angle tagging devices, to detect both high and low e^+e^- energy in e^+e^- --> e^+e^-X events, namely gamma-gamma processes. The following perspectives are presented: gamma-gamma --> pi^0pi^0 for probing light scalar meson dynamics, and gamma-gamma --> eta, gamma-gamma --> pi^0 for the determination of transition form factors. The inner tracker and small angle calorimeters are scheduled to be installed in a subsequent step, providing with larger acceptance for both charged particles and photons. We present perspectives derived using these upgrades together with increased statistics: rare eta decays, accurate study of the dominant eta' decays (e.g. eta' --> eta pi pi, to constrain scalar meson exchange) and the limit on the phi --> K_S K_S gamma branching ratio, relevant for the scalar meson structure. One possible solution to the Dark Matter problem, allowing also to interpret the positron excess measured by the satellite Payload experiment PAMELA, suggests a Hidden Sector that can be constrained by KLOE-2 at DAφNE: possible channels and impacts on the parameters space are discussed. Improvements on hadronic cross section at an energy-upgraded DAφNE are addressed, needed to understand the 3-sigma effect on (g-2)_mu and for precision determination of alpha_em at the TeV scale.
        Speaker: Paolo Gauzzi (Universita di Roma I "La Sapienza")
        Slides
      • 11:40
        Rare and Radiative Kaon Decays from the NA48 Experiment 18m
        Precision Measurement of pi pi Scattering Lengths in Ke4 Decays at NA48 The measurement of the S-wave pi pi scattering lengths is a fundamental test of the validity of Chiral Perturbation Theory. We report on the final NA48/2 result, which uses the complete NA48/2 data set with more than a million reconstructed Ke4 decays. From these events we have determined the decay form factors and pi pi scattering lengths a0_0 and a2_0. The result is the most precise measurement of the scattering lengths and in excellent agreement with the prediction of Chiral Perturbation Theory. Precision Measurement of Photon Emission in K+- --> pi+- pi0 gamma Decays at NA48 We report our final result on the measurement of direct photon emission (DE) in the decay K+- -> pi+- pi0 gamma and its interference (INT) with the inner bremsstrahlung amplitude. For this measurement the full NA48/2 data set with about 600k reconstructed K+- -> pi+- pi0 gamma decays was analyzed, which is factor of 30 larger than for previous experiments and a factor of three w.r.t. our preliminary result. From this, the sizes of both the DE and the INT amplitudes have been measured with high precision, with the INT amplitude being observed for the first time. In addition, a measurement of the CP violating asymmetry between K+ and K- has been obtained. Measurement of the rare Decay K+- --> pi+- gamma gamma at NA48 We report on the measurement of the branching fraction of the rare decay K+- -> pi+- gamma gamma using the full NA48/2 dataset of more than 5000 reconstructed decays from the full NA48/2 data set. From the spectrum of the invariant gamma gamma mass, the decay parameter c^ can be extracted with unprecedented precision. Measurement of the radiative Decay K+- --> pi0 e+- nu_e gamma at NA48 We report on the measurement of more than 200000 events of the decay K+- --> pi0 e+- nu_e gamma, recorded with the NA48/2 detector at CERN. These statistics, about two orders of magnitude more than previous experiments, allow measurements of the decay rate and of possible CP violation in this decay with per cent precision.
        Speaker: Vladimir Kekelidze (Joint Institute for Nuclear Research (JINR))
        Slides
      • 12:00
        Hadron Spectroscopy at COMPASS 13m
        The COMPASS experiment focused its physics program on hadron spectroscopy in the last two years. As a fixed target experiment at the CERN SPS accelerator, COMPASS features large acceptance and high momentum resolution and thus qualifies well for studies of diffractive dissociation and central production. Hadron formation with both 190 GeV pi-/K- amd 190 GeV p/pi+ beams on liquid hydrogen, copper and nickel was observed through the years 2004, 2008 and 2009 to search for exotic mesons and glueballs. We present an overview of the spectroscopy program which includes studies of diffractively produced 3 and 5 charged pionic final states, studies of neutral modes, kaonic final states and first results from central production analyses.
        Speaker: Frank Nerling (Fakultaet fuer Physik)
        Slides
      • 12:15
        Study light scalar mesons from heavy quark decays 13m
        It is a difficult task to probe internal structures of the scalar mesons below or near 1GeV. In the SU(3) symmetry limit, the semileptonic D^+ --> Sl^+ nu and B^+ Slnubar decays, with S=a_0, f_0 and sigma, are found to obey very different sum rules in the two scenarios for scalar mesons. Thus it can uniquely distinguish the qqbar and the tentraquark descriptions for light scalar mesons model-independently. This also applies to the B^0 --> J/psi(eta_c) S decays. The SU(3) symmetry breaking effect is found to be under control, which will not spoil our method. The branching fractions of the D^+ --> Sl^+nu, B^+ --> Sl nubar and B^0 --> J/psi(eta_c) S decays roughly have the order 10^-4, 10^-5 and 10^-6, respectively. The ongoing BES-III and the forthcoming Super B experiments are able to measure these channels and accordingly to provide the detailed information of scalar meson inner structure.
        Speaker: Prof. Cai-Dian Lu (IHEP,Beijing)
        Slides
    • 11:00 12:30
      06 - CP violation, CKM and Rare Decays Salle 242A ()

      Salle 242A

      Convener: Francesca Di Lodovico (Queen Mary University of London)
      • 11:00
        Quark and Lepton Evolution Invariants in the Standard Model 13m
        We construct a new set of Standard Model evolution invariants which link quark masses and mixing parameters. We examine their phenomenological implications and infer a simple combination of Yukawa coupling matrices which appears to play a unique role in the Standard Model. This suggests a possible new insight into the observed spectrum of quark masses. Similar evolution invariants are obtained for the leptons in the case of Dirac neutrinos.
        Speaker: Prof. Paul Harrison (University of Warwick)
        Slides
      • 11:15
        Search for B -> tau nu 11m
        We present a search for the fully leptonic B decay B+ -> tau+ nu_{tau} in 459M B/anti-B pairs collected at the Upsilon(4S) resonance using the BaBar detector. We select a sample of events with a reconstructed hadronic B decay, B- -> D0 X-, where X represents a combination of charged and neutral light mesons; in the remainder of each event we search for the B+ -> tau+ nu_{tau} signal.
        Speaker: Dr. De Nardo Guglielmo (Napoli University and INFN)
        Slides
      • 11:28
        B-> tau nu & B->D(*)tau nu decays at Belle 15m
        We present a measurement of the decay B --> tau nu in a large data sample recorded with the Belle detector at the KEKB asymmetric energy e^+ e^- collider. We obtain the branching fraction for B --> 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 a charged Higgs boson are also discussed. We also present studies of B^+ --> \bar{D}^{*0} tau^+ nu and B^+ --> \bar{D}0 tau^+ nu decays. The events are tagged by inclusively reconstructing the accompanying B meson. Measurements of branching fractions and distributions characterizing signal decays are presented.
        Speaker: Jacek Stypuła (H. Niewodniczański Institute of Nuclear Physics Kraków)
        Slides
      • 11:45
        Search for D and B leptonic decays at Belle 13m
        We search for the flavor-changing neutral current decays D0 --> mu^+ mu^- and D0 --> e^+e^-, and for the lepton-flavor violating decays D0 --> e^(+-) mu^(-+) using a large data sample collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We find no evidence for any of these decays. We obtain significantly improved upper limits on the branching fractions: BR(D0 --> mu^{+} mu^{-})<1.4 x 10^{-7}, BR(D0 --> e^+e^-)<7.9 x 10^{-8} and BR(D0 --> e^{+} mu^{-})+BR(D0 --> mu^{+}e^{-})<2.6 x 10^{-7} at the 90% confidence level. The purely leptonic decay B^+ --> l^+ nu (l = e, mu) is highly suppressed in the Standard Model due to lepton helicity mismatch but can be strongly enhanced in New Physics scenarios. We present the results of a search for the decays B^+ --> e^+ nu and B^+ --> mu^+ nu. We also present a search for B decays into invisible final states. The nu anti-nu signal is identified by fully reconstructing the accompanying B mesons and requiring no other charged particles and no extra energy deposited in the calorimeter.
        Speaker: marko staric (J. Stefan Institute, Ljubljana, Slovenia)
        Slides
      • 12:00
        New upper limit on the decay B_s -> mu mu from D0 11m
        We present the results of a search for the flavor-changing neutral current decay B0_s -> mu+ mu- using approximately 6.1 fb^{-1} of p anti-p collisions at sqrt{s}=1.96 TeV collected by the D0 experiment at the Fermilab Tevatron Collider. Compared to the previous published D0 result we have increase the amount of data analysed by a factor of 4 and improved the background rejection using a multivariate discrimination technique.
        Speaker: Brendan Casey (Fermilab)
        Slides
      • 12:13
        Search for New Physics with Rare Heavy Flavour Decays at LHCb 15m
        The LHCb experiment has the potential, during the 2010-11 run, to observe, or improve significantly the exclusion bounds on, the rare decays B_s ->mu^+mu^- and D0 -> mu^+mu^-. These studies will provide very sensitive probes of New Physics effects. High sensitivity to New Physics contributions is also achieved by searching for direct CP violation in B0 -> K* gamma, performing a time dependent analysis of B_s --> phi gamma, and making an angular study of the decay B0 -> K* mu^+ mu^-. Here also significant results are expected from the present run. Preparations for these analyses will be presented, and studies shown of how existing data, for example prompt J/psi events, can be used to validate the analysis strategy.
        Speaker: Giampiero Mancinelli (Centre de Physique des Particules de Marseille (CPPM)-Universite)
        Slides
    • 11:00 12:30
      09 - Progress in Lattice Techniques and New Results Salle 252A ()

      Salle 252A

      Convener: Sinya Aoki (University of Tsukuba)
      • 11:00
        The QCD phase diagram at low baryon density from lattice simulations 35m
        The QCD phase diagram as a function of temperature and chemical potential for baryon number is largely unknown. Straightforward Monte Carlo simulations of lattice QCD are prohibited by the so-called sign problem for systems with a non-vanishing net baryon number. After a brief introduction to the origin of the sign problem, I review some recent computational techniques valid for sufficiently small baryon chemical potentials, and summarize our current knowledge of the QCD phase diagram resulting from such simulations.
        Speaker: Owe Philipsen
        Slides
      • 11:35
        Origin of Mass, Strong Dynamics and the Lattice 30m
        One of the important missions of LHC is to probe the mechanism behind the electroweak symmetry breaking through which elementary particles, such as the W and Z gauge bosons and the quarks, acquire mass. While the most economical solution is to have the Standard Model Higgs mechanism, other possibilities exist. One such possibility is to have dynamical electroweak symmetry breaking (DEWSB) as a result of some new strong interactions at energies of the TeV scale. As the only systematically improvable non-perturbative tool, lattice gauge theory has the potential to (in)validate many non-perturbative methods developed to search for new kinds of strong dynamics that might satisfy phenomenological constraints on DEWSB, and may facilitate the interpretation of the LHC data and hopefully shed light on the origin of mass. In this talk I will give an overview of the recent efforts by the lattice community to understand strong dynamics beyond QCD.
        Speaker: George Fleming (Yale University)
        Slides
      • 12:05
        Effects of a potential fourth fermion generation on the upper and lower Higgs boson mass bounds 25m
        We study the effect of a potential fourth fermion generation on the upper and lower Higgs boson mass bounds. This investigation is based on the numerical evaluation of a chirally invariant lattice Higgs-Yukawa model emulating the same Higgs-fermion coupling structure as in the Higgs sector of the electroweak Standard Model. In particular, the considered model obeys a Ginsparg-Wilson version of the underlying SU(2)_L x U(1)_Y symmetry, being a global symmetry here due to the neglection of gauge fields in this model. Here we present our first results on the fermion mass dependence of the Higgs boson mass bound as well as its cutoff dependence at very heavy fermion masses.
        Speaker: Dr. Philipp Gerhold (Humboldt-University Berlin)
        Slides
    • 11:00 12:30
      10 - Beyond the Standard Model (theory and experimental searches) Salle 242B ()

      Salle 242B

      Convener: Christopher Hill (University of Bristol)
      • 11:00
        Spin determination of single-produced resonances at the LHC 10m
        We present techniques and analysis tools to study the production and decay of a single resonance produced at the LHC. In a model-independent way, we show how to perform analysis of the resonance decay products to ascertain the spin of the resonance, its parity and production mechanism, and its general couplings to Standard Model matter and gauge fields. Examples of spin-zero, -one, and -two resonances ranging from the Standard Model Higgs boson to the KK Graviton are considered. Though noting implications for other final states, we focus on resonances decaying to a pair of Z bosons in a fully reconstructed final state. Through detailed MC simulation including all spin correlations and major detector effects, we use the multivariate likelihood method to extract the maximal amount of information about the resonance and separate various signal hypotheses.
        Speaker: Mr. Nhan Viet Tran (Rowland Dept. of Phys. and Astron.-Johns Hopkins University)
        Slides
      • 11:15
        Search for Color Sextet Scalars in Early LHC Experiments 10m
        We explore the potential for discovery of an exotic color sextet scalar in same sign top quark pair production in early running at the LHC. We present the first phenomenological analysis at collider energies of a color sextet scalar with full top quark spin correlations included. We demonstrate that one can measure the scalar mass, the top quark polarization, and confirm the scalar resonance with 1 fb-1 of integrated luminosity. The top quark polarization can distinguish gauge triplet and singlet scalars.
        Speaker: Dr. Edmond Berger (ANL)
        Slides
      • 11:30
        Search for stopped gluinos and Heavy Stable Charged Particles at CMS in pp collisions at sqrt(s)=7 TeV 15m
        We report the preliminary results of searches for long-lived particles produced in 7 TeV pp collisions from CERN’s Large Hadron Collider. A signature-based search for heavy stable charged particles using a high transverse-momentum muon trigger was performed. The search uses time-of-flight and ionization energy loss to isolate slowly moving, heavy, high transverse momentum particles. This result is interpreted within the context of stable stop squark and gluino models. We have also looked for long-lived particles which have stopped in the CMS detector. We search for the subsequent decay of these particles during time intervals where there were no pp collisions. In particular, we search for decays during gaps between crossings in the LHC beam structure as well as the inter-fill period between the beam being dumped and re-injection using a dedicated calorimeter trigger.
        Speaker: Jim Brooke (H.H. Wills Physics Laboratory)
        Slides
      • 11:50
        Searches for Exotic Long-lived Particles using Early Data from the ATLAS Detector at the LHC 15m
        Exotic heavy long-lived particles are predicted in a range of theories which extend the Standard Model. Supersymmetry models alone allow for meta-stable sleptons, squarks and gauginos. Such particles are identifiable as they traverse the detecter by observables related to tracking, timing and energy loss which differ for Standard Model and exotic processes. Also, if a model such as split-supersymmetry is realized in nature, R-hadrons, which contain a long-lived gluino or squark, can be produced and may lose enough of their energy through ionization to become captured and stop in the densest materials. Such "stopped" particles would decay at some later time, producing a high energy deposit which can be picked up by the trigger and detector, provided they remain active. This talk presents results from searches to discover both types of particles using data from proton-proton collisions at 7 TeV centre-of-mass energy which have been accumulated by the ATLAS detector at the LHC.
        Speaker: Dr. Pasquale-Fabrizio Salvatore (University of Sussex)
        Slides
      • 12:10
        Impact of squark generation mixing on the search for squarks and gluinos at LHC 15m
        We study gluino decays, and squark production and decays, in the Minimal Supersymmetric Standard Model (MSSM) with squark generation mixing. We show that the mixing effects can be very large in a significant range of quark-flavour-violating parameters despite the very strong constraints on quark-flavour-violation (QFV) from experimental data on B mesons. We find that under favourable conditions the branching ratio of the QFV decay gluino -> c tbar (cbar t) + neutralino_1 can be as large as about 50%. We also find that the squark generation mixing can result in a multiple-edge (3- or 4-edge) structure in the charm-top quark invariant mass distribution. Further we show that the two lightest up-type squarks su_{1,2} can have very large branching ratios for the decays su_i -> charm-quark neutralino_1 and su_i -> top-quark neutralino_1 simultaneously due to the mixing effect, resulting in QFV signals 'p p -> c tbar (t cbar) + missing-E_T + X' at a significant rate at LHC. These remarkable signatures provide an additional powerful test of supersymmetric QFV at LHC. They could have an important impact on the search for gluinos and squarks and the determination of the MSSM parameters at LHC.
        Speaker: Prof. Keisho HIDAKA (Tokyo Gakugei University)
        Slides
    • 12:30 14:00
      Lunch Break 1h 30m

      Lunches not provided.

    • 14:00 15:45
      02 - The Standard Model and Electroweak Symmetry Breaking Salle 252B ()

      Salle 252B

      Convener: Prof. Stefan Dittmaier (Universitaet Freiburg)
      • 14:00
        Higgs production at the Tevatron and LHC 22m
        Higgs production cross sections, including electroweak NLO corrections will be discussed
        Speaker: Prof. Giampiero Passarino (Torino University)
        Slides
      • 14:25
        Search for Standard Model Higgs boson in gamma gamma final state at the Tevatron 18m
        We present a search for Higgs bosons decaying to the di-photon final state using 5 fb-1 of data at a center-of-mass energy of sqrt(s)=1.96~TeV at the Fermilab Tevatron collider. Whilst the branching ratio to the di-photon final state is small in the Standard Model, this channel contributes appreciably to the overall Higgs sensitivity at Tevatron. In parallel, the limit is re-interpreted in fermiophobic models where the di-photon branching ratio is considerably larger. This decay channel will be of major importance in the light mass Standard Model Higgs search at the LHC.
        Speaker: Krisztian Peters (FNAL)
        Slides
      • 14:45
        Search for Standard Model Higgs boson in di-tau final state at the Tevatron 18m
        We present a search for a Standard Model Higgs boson in events with a final state containing two taus and two jets at a center-of-mass energy of sqrt(s)=1.96 TeV at the Fermilab Tevatron collider. The final states are sensitive to a combination of associated production of a W/Z boson with a Higgs boson, vector boson fusion and gluon-gluon fusion production processes. Inclusion of the data set up to 5.4 fb-1, and recent improvements to the sensitivity will be discussed.
        Speaker: Pierluigi Totaro (INFN-Sezione di Trieste)
        Slides
      • 15:05
        Beyond Standard Model Higgs bosons searches at the Tevatron 18m
        We present a search for non-Standard Model Higgs bosons at a center-of-mass energy of sqrt(s)=1.96 TeV using up to 6 fb-1 of Tevatron data. Searches for charged and neutral Higgs bosons predicted in MSSM and NMSSM models will be discussed.
        Speaker: Abid Patwa (Brookhaven National Laboratory (BNL))
        Slides
      • 15:25
        Associated b Quark-Higgs Boson Production at the LHC 18m
        We present the one-loop electroweak effects for the process of semi-inclusive b-Higgs production at the LHC. The electroweak effects are significant for heavy Higgs bosons and can be obtained using an effective theory approach. We also discuss new results for the merging of the 4 flavor number parton distribution scheme and the 5-flavor number parton distribution scheme for the calculation of b-Higgs production at NLO. The merged scheme captures the relevant kinematic features at all scales.
        Speaker: Prof. Sally Dawson (BNL)
        Slides
    • 14:00 15:45
      03 - Perturbative QCD, Jets and Diffractive Physics Salle 242B ()

      Salle 242B

      Convener: Leszek Motyka (Hamburg University)
      • 14:00
        High-energy amplitudes in the next-to-leading order 15m
        I review the calculation of the next-to-leading order behavior of high-energy amplitudes in N=4 SYM and QCD using the operator expansion in Wilson lines.
        Speaker: Prof. Ian Balitsky (JLab/ODU)
        Slides
      • 14:17
        Inclusive Diffraction at HERA 18m
        The production of highly energetic forward neutrons has been studied in deep-inelastic positron-proton scattering. The data were taken with the H1 detector at HERA in the years 2006-2007 and correspond to an integrated luminosity of 122 pb^-1. Semi-inclusive cross sections have been measured in the range of four momentum transfer squared 6 < Q^2 < 100 GeV^2, Bjorken scaling variable 1.5 * 10^-4 < x < 3 * 10^-2 and the fractional momentum of the neutron 0.32 < x_L < 0.95. Monte Carlo simulation using the one pion exchange model describes the measurements well at low transverse momenta of the neutrons. The data are used to estimate the structure function of the pion. Measurements are presented of single and double-differential dijet cross sections in diffractive photoproduction based on a data sample with an integrated luminosity of 47 pb^-1. The events are of the type ep -> eXY, where the hadronic system X contains at least two jets and is separated by a large rapidity gap from the system Y, which consists of a leading proton or low-mass proton excitation. The dijet cross sections are compared with QCD calculations at next-to-leading order and with a Monte Carlo model based on leading order matrix elements with parton showers. The measured cross sections are smaller than those obtained from the next-to-leading order calculations by a factor of about 0.6. This suppression factor has no significant dependence on the fraction x_gamma of the photon four-momentum entering the hard subprocess. Ratios of the diffractive to the inclusive dijet cross sections are measured for the first time and are compared with Monte Carlo models. The cross section for the diffractive deep-inelastic scattering process ep -> eXp is measured, with a leading final state proton with a fractional longitudinal momentum loss x_IP satisfying x_IP < 0.1 detected in the H1 Forward Proton Spectrometer. Using a high statistics data sample for which the squared four-momentum transfer at the proton vertex is in the interval 0.1 < |t| < 0.7 GeV^2 and for photon virtualities in the range 4 < Q^2 < 700 GeV^2 the cross section is measured differentially in t, x_IP, Q^2 and beta, 0.001 < beta = x/x_IP < 1, where x is the the Bjorken scaling variable. The t and x_IP dependences are interpreted in terms of an effective pomeron trajectory and a sub-leading exchange. The data are compared with QCD predictions at next-to-leading order based on diffractive parton distribution functions previously extracted from complementary measurements of inclusive diffractive deep-inelastic scattering. The ratio of the diffractive to the inclusive ep cross section is studied as a function of Q^2, beta and x_IP. A first measurement of the longitudinal diffractive structure function F_L^D using the H1 detector at HERA is presented. The structure function is extracted from first measurements of the diffractive cross section at centre of mass energies sqrt{s} of 225 and 252 GeV, together with a new measurement at sqrt{s} of 319 GeV, using data taken in 2007 at high values of inelasticity y. The measured F_L^D is compared to predictions from NLO QCD fits to previous measurements of the inclusive diffractive DIS cross section. Measurements of the cross section for the diffractive process ep -> eXY are presented, where Y is a proton or a low mass proton excitation carrying a fraction 1-x_IP > 0.95 of the incident proton longitudinal momentum and the squared four-momentum transfer at the proton vertex satisfies |t| < 1.0 GeV^2. Using data taken by the H1 experiment, the cross section is measured for photon virtuality in the range 3.5 < Q^2 < 90 GeV^2, triple differentially in x_IP , Q^2 and beta = x/x_IP , where x is the Bjorken scaling variable. These measurements are done after selecting diffractive events showing a large rapidity interval between the hadronic systems X and Y . They cover the periods of data taking 1999-2000 and 2003-2007. Combinations with previous results obtained by H1 with data collected in 1996-1997 are realized to provide a single set of diffractive cross sections using the large rapidity gap selection from the H1 experiment. Comparisons of measurements with predictions from resolved Pomeron and dipole models are shown and discussed. In 2004, the H1 Collaboration at HERA installed the Very Forward Proton Spectrometer (VFPS) located at 220m from the interaction point, in the cold section of the proton ring. The spectrometer consists of two Roman Pot stations equipped with scintillating fiber detectors. The device allows the measurement of diffractive proton momentum in the range 0.009 < x_pom < 0.025, where x_pom is the energy fraction lost by the proton in the interaction, with a very high acceptance (above 90%). The inclusive diffractive deep inelastic scattering, ep -> e gamma* p -> e X p, has been measured with the H1 detector at HERA using VFPS to measure the scattered proton momentum. The data correspond to an integrated luminosity of 95 pb^-1. The cross section has been measured for virtualities of the exchanged boson, 5 < Q^2 < 100 GeV^2 and in the range 0.005 < beta < 0.8, where beta=x/x_pom. The cross section is measured differentially in Q^2, x_pom and beta and compared to previously measured cross section at HERA. In this measurement, the cross section for inclusive jet production in diffractive deep-inelastic scattering is presented. The leading final state proton is detected in the H1 Forward Proton Spectrometer. The data have been collected during the HERA-2 period. The data cover the range x_IP < 0.1 in fractional proton longitudinal momentum loss, 0.1 < |t| < 0.7 GeV^2 in squared four-momentum transfer at the proton vertex and 4 < Q^2 < 110 GeV^2 in photon virtuality. The dijet topology is defined by two inclusive jets in the central region, found by the k_T cluster algorithm in the hadronic centre-of-mass. The data are compared to parton shower and to NLO predictions. The production of dijets in diffractive deep inelastic scattering, ep -> e gamma* p -> e p jet1 jet2 X, has been measured with the H1 detector at HERA using Very Forward Proton Spectrometer to measure the scattered proton momentum. The data correspond to an integrated luminosity of 95 pb^-1. This process is sensitive to the partonic structure of the diffractive exchange between the proton and the virtual photon. The scattered proton is measured using the VFPS with an acceptance of about 90% in the range 0.009 < x_pom < 0.025, where x_pom is the energy fraction lost by the proton in the interaction. The dijet cross section has been measured for virtualities of the exchanged boson, 5 < Q^2 < 80 GeV^2 and photon-proton centre-of-mass energies, 100 < W < 250 GeV and |t| < 1 GeV^2. The jets were identified using the inclusive k_T algorithm in the gamma* p frame. The two highest transverse energy jets identified in each event were required to satisfy E*_{T, jet} > 5.5 and 4 GeV, respectively in the pseudorapidity range -2.0 < eta_{jet} < 2. The cross sections are compared to the predictions from leading-logarithm parton-shower RapGap Monte Carlo and next-to-leading-order QCD calculations based on recent diffractive parton densities extracted from inclusive diffractive deep inelastic scattering data. The dissociation of virtual photons, gamma* p -> X p, in events with a large rapidity gap between X and the outgoing proton, as well as in events in which the leading proton was directly measured, has been studied with the ZEUS detector at HERA. The data cover photon virtualities Q2 > 2 GeV2 and gamma* p centre-of-mass energies 40 < W < 240 GeV, with MX > 2 GeV, where MX is the mass of the hadronic final state, X . Leading protons were detected in the ZEUS leading proton spectrometer. The cross section is presented as a function of t, the squared four-momentum transfer at the proton vertex and Phi, the azimuthal angle between the positron scattering plane and the proton scattering plane. It is also shown as a function of Q2 and xIP, the fraction of the proton's momentum carried by the diffractive exchange, as well as beta, the Bjorken variable defined with respect to the diffractive exchange. ZEUS inclusive diffractive cross-section measurements have been used in a DGLAP next-to-leading-order QCD analysis to extract the diffractive parton distribution functions. Data on diffractive dijet production in deep inelastic scattering have also been included to constrain the gluon density. Predictions based on the extracted parton densities are compared to diffractive charm and dijet photoproduction data. The reduced cross section in diffractive deep inelastic scattering events, ep -> eXp, was measured with the ZEUS detector at HERA, using three different centre- of-mass energies, 318, 252 and 225 GeV. The diffractive sample was selected by requiring a large rapidity gap between the hadronic system X and the outgoing proton. The longitudinal component of the diffractive structure function of the proton was extracted. The semi-inclusive reaction e+p -> e+Xp was studied with the ZEUS detector at HERA using an integrated luminosity of 12.8 pb-1. The final state proton, which was detected with the ZEUS leading proton spectrometer, carried a large fraction of the incoming proton energy, x_L > 0.32, and its transverse momentum squared satisfied p_T2 < 0.5 GeV2; the exchanged photon virtuality, Q2, was greater than 3 GeV2 and the range of the masses of the photon-proton system was 45 < W < 225 GeV. The leading-proton production cross section and rates are presented as a function of x_L, p_T2, Q2 and the Bjorken scaling variable, x. Differential cross sections for dijet photoproduction in association with a leading neutron, e+ + p -> e+ + jet + jet + X (+ n), have been measured with the ZEUS detector at HERA using an integrated luminosity of 40 pb-1. The fraction of dijet events with a leading neutron was studied as a function of different jet and event variables. Single- and double-differential cross sections are presented as a function of the longitudinal fraction of the proton momentum carried by the leading neutron, xL, and of its transverse momentum squared, pT2. The dijet data are compared to inclusive DIS and photoproduction results; they are all consistent with a simple pion exchange model. The neutron yield as a function of xL was found to depend only on the fraction of the proton beam energy going into the forward region, independent of the hard process. No firm conclusion can be drawn on the presence of rescattering effects. Diffractive electroproduction of pion pairs at HERA has been studied with the ZEUS detector. The analysis was carried out in the kinematic range of photon virtuality 2 < Q2 < 80 GeV2, gamma*p center-of-mass energy 40 < W < 180 GeV and two-pion invariant mass 0.28 < M(pipi) < 2.3 GeV. The pi+pi- invariant-mass distribution was analyzed in terms of three isovector resonaces: rho, rho' and rho''. Masses and widths as well as relative amplitudes were obtained using a fit to the pion electromagnetic form factor. The Q2 dependence of the pion form factor was studied.
        Speaker: Paul Richard Newman (School of Physics and Astronomy-University of Birmingham)
        Slides
      • 14:37
        First complete NLL BFKL calculation of Mueller Navelet jets at LHC 15m
        We calculate cross section and azimuthal decorrellation of Mueller Navelet jets at the LHC in the complete next-lo-leading order BFKL framework, i.e. including next-to-leading corrections to the Green's function as well as next-to-leading corrections to the Mueller Navelet vertices. The obtained results for standard observables proposed for studies of Mueller Navelet jets show that both sources of corrections are of equal, big importance for final magnitude and final behavior of observables. The astonishing conclusion of our analysis is that the observables obtained within the complete next-lo-leading order BFKL framework of the present work are quite similar to the same observables obtained within next-to-leading logarithm DGLAP type treatment. This fact sheds doubts on general belief that the studies of Mueller Navelet jets at the LHC will lead to clear discrimination between the BFKL and the DGLAP dynamics.
        Speaker: Samuel Wallon (LPT, Université Paris-Sud, CNRS, Orsay and UPMC Univ. Paris 06)
        Slides
      • 14:54
        Forward jets and energy flow in hadron-hadron collisions 15m
        At the Large Hadron Collider (LHC) it will become possible for the first time to investigate experimentally the forward region in hadron-hadron collisions via high-p_T processes. In the LHC forward kinematics QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. The theoretical framework to resum consistently both kinds of logarithmic corrections to higher orders in QCD perturbation theory is based on QCD high-energy factorization. We present predictions in this framework for forward jet production, focusing on correlations between one forward and one central jet. Next we compute energy flow observables in the rapidity region between the jets and in the outside region. We finally analyze the role of parton-showering effects in the forward region arising from large-angle multi-gluon radiation, and discuss the potential impact of such studies on the modeling of multi-parton interactions.
        Speaker: Francesco Hautmann (University of Oxford)
        Slides
      • 15:11
        Characteristics and Estimates of Double Parton Scattering at the Large Hadron Collider 15m
        We evaluate the kinematic distributions in phase space of 4-parton final-state subprocesses produced by double parton scattering, and we contrast these with the final-state distributions that originate from conventional single parton scattering. Our goal is to establish the distinct topologies of events that arise from these two sources and to provide a methodology for experimental determination of the relative magnitude of the double parton and single parton contributions at Large Hadron Collider energies. We examine two cases in detail, the b-bbar-jet~jet and the 4 jet final states. After full parton-level simulations, we identify a few variables that separate the two contributions remarkably well, and we suggest their use experimentally for an empirical measurement of the relative cross section. We show that the double parton contribution falls off significantly more rapidly with the transverse momentum of the leading jet, but, up to issues of the relative normalization, may be dominant at modest values of this transverse momentum.
        Speaker: Dr. Edmond Berger (ANL)
        Slides
      • 15:28
        Hard diffractive scattering from soft color screening effects 15m
        We present a simple QCD-based model where the soft gluon rescattering between final state partons in deep inelastic scattering leads to events with large rapidity gaps and a leading proton. In the framework of this model the amplitude of the soft gluon exchanges is calculated in the eikonal approximation to all orders in perturbation theory. Both large and small invariant mass M_X limits are considered. The model successfully describes the precise HERA data on the diffractive deep inelastic cross section in the whole available kinematical range and give new insights on the density of gluons at very small momentum fractions in the proton.
        Speaker: Dr. Roman Pasechnik (Uppsala University)
        Slides
    • 14:00 15:45
      04 - Hadronic Structure, Parton Distributions, soft QCD, Spectroscopy Salle 253 ()

      Salle 253

      Convener: Volker Burkert (Jefferson Lab)
      • 14:00
        Study of a0(980)-f0(980) mixing at BESIII and study of charged kappa at BESII 8m
        There has been much arguments on whether sigma and kappa exist, due to the facts that the total phase shifts in the lower mass region are much less than 180 degrees and they do not fit into ordinary meson nonets; also whether f0(980) and a0(980) are part of the ground-state quark-antiquark family or whether they are 4-quark states, hybrids or K Kbar molecules. The study of their nature has been one of the important topics in the light hadron spectroscopy. The mixing intensity of f0(980) and a0(980) is expected to shed light on the nature of these two resonances. The a0-f0 mixing intensity has been predicted to be in the range of 0.01 to 0.2 by various theoretical models, but no any experimental results are available yet. The transition of f0(980) to a0(980) or a0(980) to f0(980) will provide complementary constraints to the parameters of a0 and f0 mesons. Using the samples of 2.26 X 10^8 J/Psi events and 1.06 X 10^8 psi' events collected with the BESIII detector, we perform direct measurements of a0-f0 mixing via the isospin breaking processes J/psi->phi f0->phi a0 and chi_c1->pi0 a0 ->pi0 f0. The preliminary results on the a0(980)-f0(980) mixing intensity are presented. Evidence for neutral kappa firstly comes from re-analysis of the old Kpi scattering data and then the production decay processes including D -> K pi pi, J/Psi -> K* K pi, etc.. Because of the isospin symmetry, a charged kappa is expected. We report the charged kappa in J/psi-> K Ks pi pi decays, based on 5.8 X 10^7 J/Psi events collected by BESII. The charged kappa particle is found as a low mass enhancement in the invariant mass spectrum of K pi. If a Breit-Wigner function of constant width is used to parameterize the kappa, its pole locates at (849 +- 77+18-14) -i (256 +- 40 +46-22) MeV/c2, which is consistent with that for neutral kappa.
        Speaker: Dr. Beijiang Liu (Institute of High Energy Phsics (CAS) and Hong Kong University)
        Slides
      • 14:10
        New Observations on Light Hadron Spectroscopy at BESIII 13m
        The decays of psi'-> pi pi J/psi (J/psi -> gamma p pbar), psi'-> gamma ppbar, J/psi-> gamma p pbar, J/psi -> gamma pi pi eta’ and J/psi -> omega pi pi eta are analyzed using the samples of 2.26 X 10^8 J/psi events and 1.06 X 10^8 psi' events collected with the BESIII detector. In psi'-> pi pi J/psi (J/psi -> gamma p pbar) decay, an enhancement at p pbar threshold is observed. The enhancement can be fit with an S-wave Breit-wigner resonances function with a mass of M=1861+6-13(stat)+7-26(syst) MeV/c2 and a narrow width Gamma < 38 MeV/c2 at the 90% confidence level. A similar structure is also observed in J/psi->gamma p pbar. These results are consistent with published BESII results. The mass and width of this structure do not match with any well established mesons. No similar narrow structure is seen in psi'->gamma p pbar. For the decays of J/psi->gamma pi pi eta', the resonance X(1835), which was observed at BESII in the same decays, is confirmed in both of the two decay modes of eta’ ( eta' -> gamma rho and eta’ -> pi pi eta). Besides, the hint for two new additional structures is revealed. The search for possible new structure in J/psi -> omega pi pi eta has also been performed.
        Speaker: huang yanping (IHEP)
        Slides
      • 14:25
        Studies with Initial State Radiation at BABAR 13m
        * Initial State Radiation Physics Studies at BABAR We present recent results obtained at BABAR from low energy e+e- annihilations, produced via initial state radiation. Low energy hadronic cross sections provide essential experimental input for calculating hadronic corrections to the muon anomalous magnetic moment, while studies of final states and intermediate structures with unprecedented accuracy can reveal new bound states and help elucidate their properties. We present new measurements of e+e- -> K+K-pi+pi-, K+K-pi0pi0, 2(K+K-) based on the full data set including investigations of signals from phi(1020)2pi and phi(1020)f_0(980) intermediate states. The evaluation of Y(2175) -> phi f_0(980) parameters are presented along with measurements of the J/psi and psi(2S) BFs to these final states. The BaBar measurement of pi^+pi^- and other channels important for calculating the hadronic contribution to the muon magnetic moment anomaly will be discussed. * Associated charm baryon production in Initial State Radiation events and measurements of the Y(4260) state produced in e+e--->gamma_ISR J/psi pi+pi- We present an analysis of a threshold enhancement observed in (Lambda_c+ anti-Lamba_c-) pairs produced in the reaction e+e--->gamma_ISR Lambda_c+ anti-Lambac-. This study uses data collected with the BABAR detector operating at the SLAC PEP-II B-factory. We also report on updated mass and width measurements for the Y(4260)--> J/psi pi+pi- produced in initial state radiation events using 454 fb^-1 of BaBar data.
        Speaker: Evgeniy Solodov (BudkerINP)
        Slides
      • 14:40
        Recent Results on Two-photon Physics at BABAR 13m
        * Recent results on two-photon physics at BABAR Two-photon processes, studied at e+e- colliders via the reaction e+ e---> e+ e- gamma gamma* --> e+ e- Pseudoscalar, provide an approach to a number of important QCD tests. We discuss the recent BABAR measurements of gamma gamma* -> pi0 transition and gamma gamma*-> eta_c transition form factors. We also report on a new measurement of the gamma gamma* -> eta and gamma gamma* -> eta' transition form factors for the momentum transfer range Q^2=4-40 GeV^2. * A study of charmonium produced in two-photon collisions at BaBar We describe a detailed study of charmonium states produced in two-photon collisions and decaying to K_S K pi and K K pi pi pi0. We present a high statistics measurement of the mass and width of the eta_c(2S) state.
        Speaker: Vladimir Druzhinin (SLAC)
        Slides
      • 14:55
        Axial Anomaly and Transition Formfactors 8m
        The earlier derived sum rule for the axial current formfactors with one real and one virtual photon is applied for the analysis of meson transition formfactors. The exactness of sum rule at all virtual photon momenta due to t'Hooft principle requires the existence of at least one axial meson which assumes the role of pion in the anomaly description at large momenta squared. The relation between pion and A1 meson formfactors is obtained and applied to the analysis of BABAR data. The possible manifestations of axial anomaly in heavy ions collisions are briefly discussed,
        Speaker: Oleg Teryaev (Joint Inst. for Nuclear Research (JINR))
        Slides
      • 15:05
        Particle Production in Two-Photon Collisions at Belle 13m
        * Experimental study of eta eta production in two-photon collisions The differential cross section for the process gamma gamma -> eta eta has been measured in the kinematic range above the eta eta threshold, 1.096 GeV < W < 3.8 GeV, in almost the whole solid angle, |cos theta*| < 0.9 or < 1.0 depending on W, where W and theta* are the energy and eta scattering angle, respectively, in the gamma gamma center-of-mass system. This is the first measurement of the cross section for this process. The results are based on a 393~fb^-1 data sample collected with the Belle detector at the KEKB e+e- collider. In the W range 1.1-2.0 GeV/c2 we perform an analysis of resonance amplitudes for various partial waves; at higher energy we extract the contributions of chi_cJ charmonia and compare the energy and angular dependence of the cross section with the predictions of theoretical models. * Observation of eta_c(2S) in six-prong final states produced in two-photon collisions We report the observation of eta_c(2S), produced in two-photon collisions, and decaying to the six-prong final states 3(pi+pi-), K+ K- 2(pi+ pi-), and K0_S K+ pi- pi+ pi- (including the charge-conjugate state). This analysis is based on a large data sample accumulated by the Belle experiment at the KEKB asymmetric-energy electron-positron collider. This is the first observation of decay modes of the eta_c(2S) other than K0_S K+ pi-.
        Speaker: Hideyuki Nakazawa (National Central University)
        Slides
      • 15:20
        Tetraquark interpretation of e+ e- -> Upsilon pi+ pi- Belle data and e+ e- -> b bbar Babar data 13m

        We study the spectroscopy and dominant decays of the bottomonium-like tetraquarks (bound diquarks-antidiquarks), focusing on the lowest lying P-wave [bq][bbar qbar] states Y_[bq] (with q=u,d), having J^PC=1^--. To search for them, we analyse the recent BaBar data obtained during an energy scan of the e+ e- -> b bbar cross section in the range of sqrt(s)=10.54 to 11.20 GeV. We find that these data are consistent with the presence of an additional b bbar state Y_[bq] with a mass of 10.90 GeV and a width of about 30 MeV apart from the Upsilon(5S) and Upsilon(6S) resonances. A closeup of the energy region around the Y_[bq]-mass may resolve this state in terms of the two mass eigenstates, Y_[b,l] and Y_[b,h], with a mass difference, estimated as about 6 MeV. We tentatively identify the state Y_bq from the R_b-scan with the state Y_b(10890) observed by Belle in the process e+e- -> Y_b(10890) -> Upsilon(1S, 2S)pi+ pi- due to their proximity in masses and decay widths. We also analyze the Belle data [K.F. Chen, et al. (Belle Collaboration), Phys. Rev. Lett. 100, 112001 (2008); I.Adachi et al. (Belle Collaboration), arXiv:0808.2445] on the processes e+ e- -> Upsilon(1S) pi+pi-, Upsilon(2S) pi+pi- near the peak of the Upsilon(5S) resonance, which are found to be anomalously large in rates compared to similar dipion transitions between the lower Upsilon resonances. Assuming these final states arise from the production and decays of the J^PC=1^-- state Y_b(10890), which we interpret as a bound (diquark-antidiquark) tetraquark state [bq][bbar qbar], a dynamical model for the decays Y_b -> Upsilon(1S) pi+pi-, Upsilon(2S) pi+pi- is presented. Depending on the phase space, these decays receive significant contributions from the scalar 0^++ states, f_0(600) and f_0(980), and from the 2^++ qqbar-meson f_2(1270). Our model provides excellent fits for the decay distributions, supporting Y_b as a tetraquark state.

        Speaker: Ahmed Ali (DESY)
        Slides
      • 15:35
        Hadronic Molecules 10m
        In the last years, a number of exciting discoveries of new hadron states have challenged our description of the hadron spectroscopy. Among these so called XYZ states, one of the most mysterious states is the well established X(3872). In Ref.[1] we performed a coupled channel calculation of the 1^++ ccbar sector including qqbar and DD* molecular configurations; in the framework of a constituent quark model which successfully describes the meson spectrum, in particular the ccbar 1^-- sector. The elusive X(3872) meson appears as a new state with a high probability for the DD* molecular component. The branching (X(3872)-> pi+pi-pi0 J/psi)/(X(3872)-> pi+pi- J/psi)=1.0+/-0.4+/-0.3 measured by Belle [2] suggest an important isospin violation, while the branching between the radiative and the strong decays (X(3872)-> J/psi gamma)/(X(3872) -> pi+pi- J/psi) with values measured by Belle 0.14+/-0.05 [2] and by BaBar 0.33+/-0.12 [3] suggests a sizable ccbar component. In this contribution we analyze the line shapes and the different branching ratios for the decay of the X(3872) measured by the Belle and BaBar Collaborations, finding a good agreement with the experimental data. Besides the X(3872), the discovery of new states at the B-factories that don't fit in the conventional qqbar assignment motivates the study of such structures in other sectors. Using the same framework as in Ref. [1], we search new molecules in the hidden charm and charm strange sectors. In the hidden charm sector we only find the controversial 1^-- Y(4008) charmonium state as a D*D* molecule. The D_s1(2460) appears as a D^*K molecule in the charm strange sector. We also explore the hidden bottom sector in the same framework. The reduction of the kinetic energy due to the mass of the b quark favors the creation of new clusters. Our constituent quark model allows to study all the sectors in an unified vision. One of expected new particles is the partner of the X(3872) meson, found as a B B*bar. Other possible molecular candidates are studied. [1] P. G. Ortega, J. Segovia, D. R. Entem, F. Fernandez, Phys. Rev. D81, 054023 (2010) [2] K. Abe et al. (Belle Collaboration), arXiV:hep-ex/0505037. [3] B. Aubert et al. (BABAR Collaboration), Phys. Rev. Lett. 102, 132001 (2009).
        Speaker: Pablo G Ortega (University of Salamanca)
        Slides
    • 14:00 15:45
      06 - CP violation, CKM and Rare Decays Salle 242A ()

      Salle 242A

      Convener: Toru Iijima (Nagoya)
      • 14:00
        Dalitz-plot analysis of B0 -> anti-D0 pi+ pi- 13m
        Constraints on the CKM Unitarity Triangle angle beta can be obtained from a time-dependent Dalitz-plot analysis of the decay B0 -> D pi+ pi-. We present preliminary results of an analysis of the B0 -> D pi+ pi- Dalitz plot using the final BaBar dataset, consisting of around 471 million BBbar pairs.
        Speaker: Dr. Thomas Latham (University of Warwick)
        Slides
      • 14:15
        CP and CPT Violation in B decays at Belle 15m
        We present a search for direct CP violation in B^+ -> J/psi K^+ decays using a large data sample collected at the Upsilon(4S) resonance with the Belle detector operating at the KEKB asymmetric-energy e^+ e^- collider. The Standard Model predicts a small direct CP asymmetry, and the experimental precision is of the same level as the expected deviation predicted by some extensions of the Standard Model. We also present measurements of time-dependent CP asymmetries in neutral B decays to charmonium final states, and a measuremen of CP-violating parameters in B0 decays to the K_S0 K^+ K^- final state, including B0 --> phi K_S0, using a time-dependent Dalitz plot analysis. CPT is expected to be a fundamental symmetry with no significant deviations. Nonetheless we can introduce an artificial perturbation parameter to the B0-anti{B}0 mixing system that violates CPT symmetry. The CPT violating parameter, which is a complex number but expected to be zero, can be probed through proper time difference distributions in correlated B meson pair decays. We present a measurement of the CPT violating parameter using the large Belle data sample.
        Speaker: Takeo Higuchi (KEK)
        Slides
      • 14:32
        Measurements of Charmless B Decays at Belle 13m
        We report the first observation of inclusive B -> X_s eta decays using a large sample of B-anti{B} pairs accumulated at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e^+e^- collider. The X_s system is a charmless inclusive state with unit strangeness, and is reconstructed using a pseudo-inclusive technique from a kaon and up to four pions, of which at most one pion is neutral. We measure a partial branching fraction for M_{X_s} < 2.6 GeV/c2 to be (25.5 +- 2.7 (stat) +- 1.6(syst) ^{+3.8}_{-14.1} (model)) x 10^{-5}. A significant fraction of this signal occurs in the region M_{X_s} > 1.8 GeV/c2, which is beyond the range of all previously measured exclusive contributions to B -> X_s eta. We also present measurements of the branching fraction and time-dependent CP violation parameters of B0 -> a_1^{+-}(1260) pi^{-+} decays, an updated measurement of the branching fraction and direct CP asymmetry for B --> pi0 pi0 and the results of a search for the charmless decays B^+ --> rho^+ omega, B^+ --> phi pi^+ and B0 --> phi pi0. We present improved measurements of the charmless decay B --> phi phi K. We update the branching fractions of B^{+-} --> phi phi K^{+-} and B0 --> phi phi K0 decays, and the measurement of related decays such as B^{+-,0} --> phi (K^+ K^-) K^{+-,0} and B^{+-,0} --> (K^+ K^-) (K^+ K^-) K^{+-,0}. In addition, we also study the charmonium decays related to the B --> phi phi K such as J/psi --> phi (K^+ K^-) and eta_c--> phi phi.
        Speaker: Min-Zu Wang (Physics Department-National Taiwan University (NTU))
        Slides
      • 14:45
        Studies of Charmless Hadronic B-meson Decays at BABAR 13m
        We report a number of recent meaurements of B-meson decays to purely hadronic final states that do not contain charm mesons. These studies are based on the very large sample of B\overline{B} events collected by the BABAR detector at SLAC's e+e- asymmetric collider B-factory when it operated on the Upsilon(4S). We include in this paper the results of: a Dalitz plot analysis of B0->KsKsKs which provides a determination of the total branching fraction and those of intermediate states; a Dalitz plot analysis of B0->K+pi-pi0 which involves the measurements of rates, differences and direct CP violation parameters of all intermediate states and with which we place constraints on the apex of the CKM unitarity triangle; inclusive branching fraction measurements of B0->pi+KsK- and of B+->K+pi0pi0; a search for B-meson decays to the axial-vector vector final state a1+ K*0 and the search for the vector vector final state B+ -> rho0 K*+ and, for cases where a signal is present, we include studies of longitudinal polarization fractions; and measurements of B-meson decays to eta' rho, eta' f_0 and eta' K* where K* stands for a vector, scalar, or tensor strange meson and in which we also measure, where applicable, the charge asymmetries.
        Speaker: Alessandro Gaz (Department of Physics-University of Colorado)
        Slides
      • 15:00
        Prospects for CP violation measurements with charmless hadronic B meson decays at LHCb gamma measurements 11m
        Studies of two- and tree-body charmless hadronic decays of B mesons have high sensitivity to possible contributions from New Physics. Precision measurements involving these decays will be performed at LHCb, notably those of CP-violating asymmetries. These measurements benefit from a trigger system which is very efficient for hadronic final states and excellent particle identification capabilities. The full programme will be reviewed and first studies with 2010 data will be presented.
        Speaker: Ignacio De Bediaga Hickman (Centro Bras. de Pesquisas Fisicas (CBPF))
        Slides
      • 15:13
        Studies of charmed hadronic B decays with early LHCb data and prospects for gamma measurements 11m
        We present the first studies of decays of the type B -> DX, where D represents a charmed meson (D0, D(*)+ or D_s) from the LHCb experiment at CERN. Our studies use data accumulated during the 2010 run of the LHC. This work represents the first steps on a programme towards a precision measurement of the angle gamma of the CKM Unitarity Triangle. The prospects for this gamma measurement will be reviewed.
        Speaker: Susan Haines (University of Cambridge)
        Slides
      • 15:26
        Quantum-correlated D-decays at CLEO-c 17m
        The 818 fb-1 dataset collected at the psi(3770) resonance at CLEO-c offers unique possibilities for measuring strong phase differences in neutral D decays. The measurements require that both D mesons in the event are fully reconstructed, usually with one decaying to the signal mode of interest, and the other to a CP-eigenstate. The strong phase differences extracted from these decays are important inputs to measurements of D-mixing parameters and the determination of the CKM angle gamma in B -> D K decays. Results will be presented from a variety of D decays including KS pi pi, KS K K and other 3- and 4-body modes. The impact of these results on gamma measurements will be discussed.
        Speaker: Guy Wilkinson (Nuclear Physics Laboratory)
        Slides
    • 14:00 15:45
      09 - Progress in Lattice Techniques and New Results Salle 252A ()

      Salle 252A

      Convener: Shoji Hashimoto (High Energy Accelerator Research Organization (KEK))
      • 14:00
        Recent progress on nuclear potentials from lattice QCD 30m
        I review the recent progress on the determination of potentials between baryons from lattice QCD, based on works by HAL (Hadron to Atomic nuclei from Lattice) QCD Collaboration, who uses the Bethe-Salpter amplitudes to extract potentials in quantum field theories. The method is first applied to two nucleons on the lattice with quenched QCD simulations. By disentangling the mixing between the S-state and the D-state, both central and tensor potentials in the leading order of the velocity expansion of the non-local NN potential are obtained. The method has also been applied to hyperon-nucleon potentials and hyperon-hyperon potentials. The possible extension of the method to extract hadron interactions in general from lattice QCD is also discussed.
        Speaker: Prof. Sinya Aoki (University of Tsukuba)
        Slides
      • 14:30
        The excited hadron spectrum in lattice QCD using a new variance reduction method 25m
        Progress in determining the spectrum of excited baryons and mesons in lattice QCD is described. Large sets of carefully-designed hadron operators have been studied and their effectiveness in facilitating the extraction of excited-state energies is demonstrated. A new method of stochastically estimating the low-lying effects of quark propagation is proposed which will allow reliable determinations of temporal correlations of single-hadron and multi-hadron operators.
        Speaker: Prof. Colin Morningstar (Carnegie Mellon University)
        Slides
      • 14:55
        Nucleon Structure using twisted mass fermions 25m
        We present recent results on the nucleon form factors and low moments of generalized parton districbutions. They are obtained using two degenerate flavors of dynamical twisted mass fermions corresponding to pion masses in the range of about 260-450 MeV. Finite volume and cut-off effects are investigated. Chiral extrapolations of the magnetic moment, Pauli and Dirac radii and the axial charge to the physical point are discussed.
        Speaker: Constantia Alexandrou (University of Cyprus)
        Slides
      • 15:20
        Alpha_s from Lattice QCD: progresses and perspectives for a realistic full-QCD determination of the running Strong coupling 25m
        QCD is believed to be the theory of the strong interactions with, as only inputs, one mass parameter for each quark species and the value of the QCD coupling constant at some energy or momentum scale in some renormalization scheme. This is Lambda_QCD, the only non-perturbative parameter in the limit of massless quarks, to be taken from experiment, and the one which expresses the scale of strong interactions and drives the running of the QCD coupling. The QCD running coupling can be also obtained from lattice computations, the free parameters being adjusted from experimental numbers, masses, decay constants etc. As far as the non-perturbative lattice computation could be realistic, a comparison with direct experimental determination of the strong coupling, at different transferred momenta, would be in order. In this talk, the last new results concerning the lattice evaluation of the running QCD coupling constant will be discussed.
        Speaker: jose Rodriguez-Quintero (University of Huelva)
        Slides
    • 14:00 15:45
      10 - Beyond the Standard Model (theory and experimental searches) Salle Maillot ()

      Salle Maillot

      Convener: Christopher Hill (University of Bristol)
      • 14:00
        Supermodels: Early new physics at the LHC? 15m
        We explore which new physics signatures could be discovered in the first year of the LHC, beyond the expected sensitivity of the Tevatron data and other constraints. We construct "supermodels", for which the LHC sensitivity even with only 10 pb-1 useful luminosity is greater than that of the Tevatron with 10 fb-1. The simplest scenarios involve s-channel resonances in the quark-antiquark and especially in the quark-quark channels. We concentrate on easily visible final states with small standard model backgrounds, and find that there are simple searches, besides those for Z' states, which could discover new physics in early LHC data. Many of these are well-suited to test searches for "more conventional" models, often discussed for larger data sets.
        Speaker: Zoltan Ligeti (Lawrence Berkeley National Laboratory)
        Slides
        Video
      • 14:20
        Early Searches with Jets with the ATLAS Detector at the LHC 15m
        We summarize the analyses of high-pt jets in early pp collisions recorded with the ATLAS detector. The data are confronted with Standard Model predictions with the goal of searching for new phenomena: resonances, gravitationally mediated effects, and contact interactions.
        Speaker: Dr. Georgios Choudalakis (University of Chicago, Enrico Fermi Institute)
        Slides
        Video
      • 14:40
        Search for new Physics in the dijet mass spectrum and dijet ratio in pp Collisions at sqrt(s) = 7 TeV 15m
        We report on a search for new physics in dijet production at CMS, using the first pp collision data at sqrt{s}=7 TeV provided by CERN's Large Hadron Collider. The measured dijet mass spectrum is compared with QCD predictions. We use the dijet mass spectrum to search for dijet resonances that could come from several models, such as, axigluons, flavor univerals colorons, excited quarks or E6 diquarks.We have also measured the production ratio for events with two leading jets in two regions of pseudorapidity. The dijet centrality ratio, N(|η| < 0.7)/N(0.7 < |η| < 1.3), is sensitive to dijet angular distributions. The dijet centrality ratio is measured in bins of dijet mass, compared with the predictions of QCD, and used to search for the following new physics models: quark contact interactions and excited quarks.
        Speaker: Konstantinos Kousouris (Fermilab)
        Slides
        Video
      • 15:00
        Effective operators in top physics 15m
        I will show how the general trilinear interactions of the top quark (or any other fermion) arising from dimension-six gauge invariant operators are simplified when several operators in the Buchmuller & Wyler list, recently found to be redundant (arxiv:0811.3842, arxiv:0904.2387) are dropped. I will present some practical applications of this simplification for phenomenology, including the study of top FCNC processes (arxiv:1003.3173).
        Speaker: Juan Antonio Aguilar Saavedra (University of Granada and LIP)
        Slides
        Video
      • 15:20
        Search for T-Tbar Resonances at the Tevatron 15m
        We describe searches for resonant top-antitop production at the Tevatron. Resonant top pair production could arise from the decays of massive Z-like bosons in extended gauge theories, KK states of the gluon or Z, axigluons, topcolor, and other BSM theories. We use different techniques to study the top-antitop invariant mass spectrum and set model independent limits on new resonant top-antitop production mechanisms that would appear as bumps in invariant mass
        Speaker: Nathan Goldschmidt (Univ. of Florida)
        Slides
        Video
    • 14:00 15:45
      11 - Particle Astrophysics and Cosmology Salle 251 ()

      Salle 251

      Convener: Aurelien Barrau (LPSC Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Grenoble)
      • 14:00
        Cosmology with Wide Field Astronomy 17m
        Wide field astronomy has recently produced important results for the dark matter and dark energy problematics. I will summarize the scientific impact of the ongoing wide field surveys and focus on the future LSST program (Large Synoptic Survey Telescope). This program will use a 8.4 m diameter telescope, equipped with a 3.2 Gpixel wide field camera. Cosmological studies is one of his main objectives.
        Speaker: Marc Moniez (IN2P3-CNRS)
      • 14:20
        Modified Gravity and Degravitation 17m
        The idea of degravitation is to account for the small late time acceleration of the Universe by modifying gravity at large distances. After reviewing the fundamental aspects of degravitation, I will discuss the importance of interactions in models that can exhibit degravitation, and present the Galileon as a broader class of modifications of gravity. Finally I will establish a link between the Galileon and the DBI action unifying models of early Universe inflation with that of late time degravitation.
        Speaker: Prof. Claudia de Rham (Geneva University)
        Slides
      • 14:40
        The CHASE laboratory search for chameleon dark energy 13m
        A scalar field is a favorite candidate for the particle responsible for dark energy. However, few theoretical means exist that can simultaneously explain the observed acceleration of the Universe and evade tests of gravity. The chameleon mechanism, whereby the properties of a particle depend upon the local environment, is one possible avenue. I present the results of the Chameleon Afterglow Search (CHASE) experiment, a laboratory probe for chameleon dark energy. CHASE marks a significant improvement over other searches for chameleons both in terms of its sensitivity to the photon/chameleon coupling as well as its sensitivity to the classes of chameleon dark energy models and standard power-law models. Since chameleon dark energy is virtually indistinguishable from a cosmological constant, CHASE tests dark energy models in a manner not accessible to astronomical surveys.
        Speaker: Jason Steffen (Fermilab)
        Slides
      • 14:55
        Dark Energy density in Split SUSY models inspired by degenerate vacua 13m
        It is well known that in no--scale supergravity global symmetries protect local supersymmetry (SUSY) and a zero value for the cosmological constant. The breakdown of these symmetries that ensures the vanishing of the vacuum energy density near the physical vacuum leads to the natural realization of the multiple point principle (MPP) assumption, i.e. results in the set of degenerate vacua with broken and unbroken local supersymmetry. We present the minimal SUGRA model where the MPP assumption is realised naturally at the tree--level. In thisodel vacua with broken and unbroken local supersymmetry in the hidden sector (first and second phases) have the same energy density without any extra fine-tuning. Although hidden sector does not give rise to the breakdown of supersymmetry in the second phase SUSY may be broken there dynamically in the observable sector. Then a positive value of the energy density in the second vacuum is induced which can be assigned, by virtue of MPP, to all other phases including the one in which we live. The total vacuum energy density is naturally tiny or zero in this case. If gauge couplings in the physical and second vacua are the same then the dark energy density depends on the SUSY breaking scale in the physical vacuum only. Assuming Split SUSY type spectrum we argue that the observed value of the cosmological constant can be reproduced if the masses of squarks and sleptons are of order of 10^10 GeV.
        Speaker: Dr. Roman Nevzorov (University of Hawaii)
        Slides
      • 15:10
        Reheating Temperature after Inflation in String-inspired Supergravity 13m
        By using a string-inspired modular invariant supergravity model, which was proved well to explain WMAP observations appropriately, a mechanism of preheating just after the end of inflation is investigated. By using the canonically normalized and diagonalized scalars, the decay rates of these fields are calculated inflaton S into gauge sector fields. The reheating temperature is estimated by both the stability condition of Boltzmann equation and the instant preheating mechanism. Both of reheating temperatures are almost the same order of magnitude ~ O(10^10) GeV. Because two mechanisms are completely independent processes, the former is caused through the inflaton decays into gauge fields and gauginons and the latter is caused by the scattering process of two inflatons into two right handed sneutrinos, which will decay into Higgs fields and other minimal SUSY standard model (MSSM) particles, we conclude that both mechanisms play essential roles in the preheating process after inflation.
        Speaker: Mitsuo J. Hayashi (Tokai University)
        Slides
      • 15:25
        Gravitational wave detectors: First astrophysical results and path to next generation 17m
        After several years of construction and commissioning, LIGO, GEO600 and Virgo gravitational waves detectors have reached or exceeded their foreseen sensitivities and are in operation for few years. Even if a first detection remains unlikely with these sensitivities, meaningful results from the astrophysical point of view have been obtained on gamma-ray bursts or pulsars for example. For the current joint scientific run of LSC and Virgo collaborations, the "multi-messenger" approach has reached maturity and, in particular, online searches have been implemented in order to trigger external observations by satellites or telescopes. We hope that this "multi-messenger" strategy will be fruitful when the next generation of detectors will perform their first science runs in 2015. With a sensitivity increased by a factor 10, gravitational wave events should become frequent and will allow a better understanding of the source physics.
        Speaker: Dr. Fabien Cavalier (Laboratoire de l'Accelerateur Lineaire Orsay)
        Slides
    • 15:45 16:15
      Coffee Break 30m
    • 16:15 18:00
      02 - The Standard Model and Electroweak Symmetry Breaking Salle 252B ()

      Salle 252B

      Convener: Dmitri Denisov (Fermi National Accelerator Laboratory (FNAL))
      • 16:15
        Status of the global fit to electroweak precisions data, and constraints on the Higgs boson 18m
        Gfitter results from the global Standard Model (SM) fit to electroweak precision data, including newest Tevatron measurements, are reviewed and discussed. Constraints on the Higgs and top-quark masses, as well as on alpha_s(M_Z), are studied in some detail, and outlooks to the LHC and ILC eras are presented. Information from the electroweak fit on loop contributions from beyond-SM models is obtained through an analysis of the so-called oblique parameters.
        Speaker: Martin Goebel (DESY - University of Hamburg)
        Slides
      • 16:35
        Combination of Standard Model and beyond Standard model Higgs searches at DZero 20m
        A combination of searches for Standard Model and beyond Standard Model Higgs boson production at DZero using a data sample up to 7 fb-1 of integrated luminosity is performed. For Standard Model searches we determine combined upper 95% C.L. limits on the ratio of the Higgs boson cross section times the branching ratio to its Standard Model prediction for Higgs boson masses between 100 and 200 GeV/c2.
        Speaker: Michael Mulhearn (University of Virginia)
        Slides
      • 16:57
        Combination of Standard Model and beyond Standard model Higgs searches at CDF 20m
        A combination of searches for Standard Model and beyond Standard Model Higgs boson production at CDF using a data sample up to 6.0 fb-1 of integrated luminosity is performed. For Standard Model searches we determine combined upper 95% C.L. limits on the ratio of the Higgs boson cross section times the branching ratio to its Standard Model prediction for Higgs boson masses between 100 and 200 GeV/c2.
        Speaker: Karolos Potamianos (Purdue University)
        Slides
      • 17:19
        ATLAS Higgs Sensitivity for 1/fb of data at the LHC running at 7 TeV 18m
        The search for Higgs bosons at the Large Hadron Collider (LHC) is based on the analysis of independent final states, such as photon, tau, W and Z pairs. The Higgs discovery potential of ATLAS for each independent final state, as well as for combined channels, is reviewed and discussed. Results are presented for an integrated luminosity for 1/fb at 7 TeV center of mass energy at the LHC. Practical methods to estimate the backgrounds using control samples in real data are discussed. Validation of some of the data driven background estimation methods using the early 7 TeV ATLAS data at the LHC is also presented.
        Speaker: Tatsuya Masubuchi (University of Tokyo)
        Slides
      • 17:39
        Prospects for Higgs boson searches with CMS 18m
        We overview the prospects for Higgs boson searches with a data sample of 1 fb-1 to be collected in pp-collisions at 7 TeV. We present sensitivity projections for SM-like decay modes H→WW→2l2v, H→ZZ→4l, H→ γγ (including their combination), the MSSM-like signature pp→bbΦ→bb(ττ), and, also discuss a few other possible models/searches. Preliminary results of data analyses validating a number of the key aspects of these Higgs searches are also reported.
        Speaker: Dr. Marat Gataullin (Caltech)
        Slides
    • 16:15 18:00
      03 - Perturbative QCD, Jets and Diffractive Physics Salle 242B ()

      Salle 242B

      Convener: Gudrun Heinrich (University of Durham)
      • 16:15
        Status of Higher Order QCD calculations 17m
        All physics reactions at the LHC are initiated by partonic processes, which are determined by QCD. To interpret potential signals and their backgrounds, one thus requires a solid understanding of the QCD dynamics, which is achieved by including higher order perturbative corrections. We review the recent progress on higher order calculations in QCD, focusing on the calculation of multi-leg processes at next-to-leading order (NLO) and on precision observables at next-to-next-to-leading order (NNLO). We summarize recent results and important physics implications, and discuss technical developments for the systematic calculation of QCD corrections.
        Speaker: Aude Gehrmann-De Ridder (ETH Zurich)
      • 16:35
        Higgs boson production at LHC to NNLO accuracy and finite top quark mass effects 15m
        In this talk we consider the production of the Standard Model Higgs boson in the gluon fusion process to NNLO. An approach is presented which allows the calculation of the cross section beyond the heavy-top quark approximation thus leading to results which include the effects of a finite top quark mass. Numerical results are shown for the CERN Large Hadron Collier (LHC).
        Speaker: Prof. Matthias Steinhauser (KIT)
        Slides
      • 16:52
        NLO QCD corrections to pp -> t anti-t b anti-b 15m
        The production of t anti-t b anti-b final states represents one of the most important beackground processes for Higgs production in association with top-quark pairs at the LHC. A good background control is indispensible for an analysis of the ttH(->bb) signal, requiring next-to-leading order (NLO) predictions for both signal and background. The talk describes a recently completed NLO QCD calculation for pp->ttbb at the LHC, a calculation that is at the calculational frontier of NLO predictions for so-called multi-leg processes. Moreover, results from a phenomenologically driven analysis are discussed.
        Speaker: Prof. Stefan Dittmaier (Universitaet Freiburg)
        Slides
      • 17:09
        Top-Antitop Production at Hadron Colliders 15m
        We review the status of the theoretical predictions for the top-anti top production in hadronic collisions, paying particular attention to the pair production at the LHC. We stress the need for a complete theoretical analysis that includes higher-order quantum corrections and we discuss recent theoretical calculations at the level of NNLO.
        Speaker: Roberto Bonciani (LPSC, Grenoble)
        Slides
      • 17:26
        NNLL resummation for QCD cross sections 15m
        I present results for the resummation of soft-gluon contributions to QCD hard-scattering cross sections at next-to-next-to-leading logarithm accuracy. A key ingredient is the calculation of two-loop soft anomalous dimensions for the partonic processes. Explicit expressions and applications are provided for processes that involve massless partons and/or massive quarks.
        Speaker: Prof. Nikolaos Kidonakis (Kennesaw State University)
        Slides
      • 17:43
        Adler Function, DIS sum rules and the Crewther Relation in order alpha_s^4 15m
        We report on the first analytical, valid for a generic gauge group, calculations of the O(alpha_s^4) corrections to the Adler function and to DIS sum rules, in particular to the the Gross-Llewellyn Smith and to the Bjorken ones. We discuss a decisive check of correctness of our previous calculations of R(s) in QCD and the quenched QED beta-function at five loops, which was carried out with the help of the newly computed contributions to the DIS sum rules and the Crewther relation.
        Speaker: Dr. Konstantin Chetyrkin (Karlsruhe Institute of Technology (KIT))
        Slides
    • 16:15 18:00
      04 - Hadronic Structure, Parton Distributions, soft QCD, Spectroscopy Salle 253 ()

      Salle 253

      Convener: Volker Burkert (Jefferson Lab)
      • 16:15
        Studies of Radiative Decays and Search for X(3872) at BABAR 13m
        * A study of radiative Upsilon(2S) and Upsilon(3S) transitions using converted photons We present a study of the radiative transitions from decays of the Upsilon(2S) and Upsilon(3S) resonances using photons that have converted into an e+e- pair. This study uses data collected with the BABAR detector operating at the SLAC PEP-II B-factory on the Upsilon(2S) and Upsilon(3S) resonances. * Search for f_J(2220) Production in Radiative J/psi Decays We present a search for f_J(2220) production in radiative J/psi -> gamma f_J(2220) decays using 460 fb-1 of data collected with the BaBar detector at the PEP-II storage rings. The f_J(2220) is reconstructed in the decays f_J(2220) -> K+K- and f_J(2220) -> K0_S K0_S$. No evidence of this resonance is observed and 90% confidence level upper limits on the J/psi -> gamma f_J(2220), f_J(2220) -> K+ K- and J/psi -> gamma f_J(2220), f_J(2220) -> K0_S K0_S branching fractions are set at the level of 10^-5. * The search for new X(3872) decay modes and for the Z1 and Z2 states in chi_c1 pi We present a search for the X(3872) produced in B-->psi pi+pi- K and B-->psi pi+pi-pi0 K (psi=J/psi or psi(2S)) using 427 fb-1 of BaBar data. We also report on a search for the Z1 and Z2 states in the chi_c1 pi invariant-mass distribution at BaBar. We perform a study of charged and neutral B decays to chi_c1 K pi. The aim is to search for the two resonance-like structures, the Z1 and Z2, first observed by the Belle experiment in the chi_c1 pi+ invariant-mass distribution near 4.1 GeV in exclusive B0->chi_c1 K-pi+.
        Speaker: Arafat Gabareen Mokhtar (SLAC / Stanford University)
        Slides
      • 16:30
        Charmed Hadron Physics at Babar 13m
        * Study of the inclusive production of the D pi and D* pi final states We present a study of the mass spectra of the D+pi-, D*+pi-, and D0pi+ final states in search for unobserved excited states of the D mesons. We use a dataset corresponding to ~454 fb^-1 of e+e- collisions collected by the BABAR detector at center-of-mass energies near 10.58 GeV. The final states are reconstructed inclusively in reactions of the kind e+e- -> ccbar -> D^(*)pi X where X is any additional system. The ccbar events are selected through a cut on the center-of-mass momentum of the D^(*)pi system. * Precision Measurements of the Angular Momentum Excited Charmed Baryon Lambda_c(2880)+ decaying to the Lambda_c+ pi+ pi- state We report results on the measurements of the charmed baryon Lambda_c(2880)+ decaying to the Lambda_c+ pi+ pi- state using approximately 354 fb^-1 of BaBar data. We reconstruct the Lambda_c+ candidates in the decay mode p K pi with a goal of measuring the mass, intrinsic width, cross section and momentum spectra of the resonances decaying into Lambda_c+ pi+ pi- final states. We also report the first measurements on the relative branching fractions of the Lambda_c(2880)+ decaying to the 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- mode.
        Speaker: Jose Benitez (SLAC)
        Slides
      • 16:45
        Studies of Radiative Decays and X(3872) production at Belle 18m
        * Search for 1P -> 1S radiative transitions of D mesons We present a search for B- -> pi- D^**0, D^**0 -> gamma D0 with a data sample from the Belle detector at the KEKB e+e- collider containing 771 x 10^6 BBbar pairs. In preliminary studies, we found that the corresponding pionic decays, D^**0 -> pi0 D0 are important backgrounds. These modes have not previously been studied; we measure them in the same data sample, in order to constrain the background component in the final fit to the gamma D0 mass distribution. * Study of radiative decays of chi_(c1,c2) and X(3872) at Belle We present a study of the radiative decays of the chi_(c1,c2) and X(3872), produced in B decays. The results are based on a large data sample collected at the Upsilon(4S) resonance with the Belle detector operating at the KEKB asymmetric-energy e+e- collider. * Search for charmonium and charmonium-like states in Upsilon(1S) radiative decays Using a large sample (10^8) Upsilon(1S) events collected with the Belle detector, we present the results of a first search for charge parity even charmonium and charmonium-like states in Upsilon(1S) radiative decays. No significant chi_(cJ), eta_c, X(3872), X(3915), or Y(4140) signal is observed, and upper limits on the production rates are determined. Furthermore, no significant evidence for excited charmonium states below 4.8 GeV/c2 is observed. * Study of X(3872) production in B meson decays We present a study of the X(3872) meson produced in decays of neutral and charged B mesons. The results are based on a large data sample collected at the Upsilon(4S) resonance with the Belle detector operating at the KEKB asymmetric-energy e^+e^- collider.
        Speaker: Ian Watson (University of Sydney)
        Slides
      • 17:05
        Studies of Upsilon Decays at Belle 18m
        * Measurement of Upsilon(5S) decays to B0 and B+ mesons Decays of the Upsilon(5S) resonance to channels with B+ and B0 mesons are studied using a 23.6 fb^-1 data sample collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. Fully reconstructed B+ -> J/psi K+, B0 -> J/psi K*0, B+ -> Dbar0 pi+ and B0 -> D- pi+ decays are used to obtain the charged and neutral Bproduction rates per b-bbar event, f(B+) = (72.1 ^(+3.9)_(-3.8) +/- 5.0)% and f(B0) = (77.0 ^+(5.8)_(-5.6) +/-6.1)%. Assuming equal rates to B+ and B0 mesons in all channels produced at the Upsilon(5S) energy, we measure the fractions for transitions to two-body and three-body channels with B meson pairs, f(B-Bbar) = (5.5^(+1.0)_(-0.9)+/- 0.4)%, f(B Bbar*+B*Bbar) = (13.7 +/- 1.3 +/- 1.1)%, f(B* Bbar*) = (37.5^(+2.1)_(-1.9) +/- 3.0)%, f(B Bbar pi) = (0.0 +/- 1.2 +/- 0.3)%, f(BBbar* pi+B* Bbar pi) = (7.3^(+2.3)_(-2.1) +/- 0.8)%, and f(B* Bbar* pi) = (1.0^(+1.4)_(-1.3) +/- 0.4)%. The latter three fractions are obtained assuming isospin conservation. *Observation of an enhancement in e+e- -> Upsilon(1S) pi+ pi-, Upsilon(2S) pi+ pi-, and Upsilon(3S) pi+ pi- production around sqrt(s)=10.89 GeV at Belle We measure the production cross sections for e+e- -> Upsilon(1S) pi+ pi-, Upsilon(2S) pi+ pi-, and Upsilon(3S) pi+ pi- as a function of sqrt(s) between 10.83 GeV and 11.02 GeV. The data consists of 8.1 fb^-1 collected with the Belle detector at the KEKB e+e- collider. We observe enhanced production in all three final states that does not conform well with the conventional Upsilon(10860) lineshape. * Search for Upsilon(2S) -> eta_b gamma and Upsilon(2S) -> eta Upsilon The Belle experiment has integrated a record sample of 160M Upsilon(2S) decays on the resonant peak. First results of searches for rare radiative transitions (Upsilon(2S) -> eta_b(1S) gamma and chi_b0(1P) -> Upsilon(1S) gamma), and the hadronic transition Upsilon(2S) -> eta Upsilon will be presented.
        Speaker: Mauro Verzetti (INFN Torino)
        Slides
      • 17:25
        Exotic J/psi Phi Structures and Search for the Z(4430)+ State at CDF 13m
        * Updated studies of exotic J/psi phi structures at CDF We report updated studies of the J/psi phi mass spectrum in exclusive B+ --> J/psi phi K+ decays collected by the CDF experiment. Using an increased data sample of 5 fb^-1 and by adding new triggers we establish observation of the Y(4140) state in its J/Psi Phi decay and provide more precise measurements of its properties. * Search for multiquark Z(4430)+ state in hadron collisions The observation of the Z(4430)+ resonance, the first solid candidate exotic multiquark state, has been reported by the Belle experiment but not confirmed by Babar. Any information from the Tevatron could be discriminating in establishing or excluding its existence. We report the first search for exotic Z(4430)+ state in hadron collisions, using 5.7 fb^-1 of data collected by the CDF detector at the Tevatron collider.
        Speaker: Kai Yi (Physics and Astronomy Department-University of Iowa)
        Slides
      • 17:40
        Charm baryon spectroscopy at CDF 18m
        We present a study of the first orbital excitations of the Lambda_c baryon, the resonances Lambda_c(2595) and Lambda_c(2625), in the decay channel Lambda_c+ pi+ pi- as well as the Lambda_c spin excitations Sigma_c(2455) and Sigma_c(2520) in its decays to Lambda_c+ pi- and Lambda_c+ pi+ reconstructed in a sample corresponding to 5.3 fb^-1 of data collected by the CDF experiment. Exploiting the excellent CDF mass resolution we present measurements of the mass differences with respect to the Lambda_c and the decay widths of these states using significantly higher statistics than previous experiments. The lineshape modification of Lambda_c(2595) due to its dominant threshold decay to Sigma_c(2455) pi is properly taken into account.
        Speaker: Felix Wick (Karlsruhe)
        Slides
    • 16:15 18:00
      06 - CP violation, CKM and Rare Decays Salle 242A ()

      Salle 242A

      Convener: Toru Iijima (Nagoya)
      • 16:15
        Measurements of the CKM angle gamma at BABAR 13m
        Using data from approximately 470 million B-Bbar pair events collected with the BaBar detector at SLAC's PEP-II e+e- B-factory running on the Upsilon(4S), we have made a number of measurements that are sensitive to the Cabibbo-Kobayashi-Maskawa CP-violating angle gamma. These include a measurement of gamma from a Dalitz Plot analysis of neutral D meson decays to K^0_S pi^+ pi^- and K^0_SK^+K^- produced in the processes B^(-+) --> D K^(-+), B^(-+) --> D^{*} K^(-+) with D^{*} --> D pi^0,D gamma, and B^(-+) --> DK^{*-+} with K^{* -+} --> K_S^0 \pi^(-+). We also search for b --> u transitions in B^- --> D^0K^- and B^- --> D^{*0} K^- decays which are sensitive gamma due to interference between the b --> c transition B^- --> D^{(*)0}K^- followed by the doubly Cabibbo-suppressed decay D^0 --> K^+ pi^-, and the b --> u transition B^- --> D^{(*)0}K^- followed by the Cabibbo-favored decay anti-{D}^0 --> K^+ pi^-. We also analyze the decay B^- --> D^{(*)} pi^- with the D decaying into the doubly Cabibbo-suppressed mode D --> K^+\pi^-. In addition we report on a measurement of the gamma in B^(+-)--> D_CP K^(+-) decays: from reconstructed B^(+-) --> D K^(+-) decays, where the neutral D meson is reconstructed in both CP-eigenstate and non-CP-eigenstate final states, we measure the partial rate charge asymmetries for CP-even and CP-odd D final states and the ratios between the charge-averaged B^(+-) --> D K^(+-) decay partial rates, where the D meson decays to CP and non-CP eigenstates. We infer frequentist confidence intervals for gamma, for the strong phase delta_B, and for the amplitude ratio r_B, which are related to the B^(+-)-->DK^(+-) decay amplitudes by r_Be^{i(\delta_B-\gamma)} = A(B^- --> \overline{D^0} K^-)/A(B^- --> D^0 K^-).We also report on the study of the decay B^- --> D^{0} (\overline D^{0}) K^-, where the D^0 or \overline D^{0} decay to K^+ pi^- pi^0. We measure the ratios of the suppressed to favored branching fractions as well as the CP asymmetries of those modes. Since the amplitudes for the processes B^+--> \overline D^{0} K^+ and B^+ --> D^{0} K^+ are proportional to V_{cb} and V_{ub}, respectively, these decays are sensitive to the weak phase gamma as well as to the magnitude r_B of the ratio between the two amplitudes. Finally, we report on the results of a search for the decays B^+ --> D^{+} K^{(*)0}.
        Speaker: Fernando Martinez-Vidal (Universidad de Valencia)
        Slides
      • 16:30
        Hadronic b -> c decays at Belle 13m
        We present a measurement of the unitarity triangle angle phi_3 using Dalitz plot analysis of three-body neutral D decays from the B^+ --> D^{(*)}K^{(*)+} process. The results are based on a large sample of B anti-{B} pairs recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB e^+e^- collider. The decay B --> D^{(*)} K^{(*)} (D = D0 or anti-{D}0) includes the b --> u transition and plays a crucial role in the measurement of the CP-violating angle phi_3. We present the result of a study of the decay B --> D^{(*)} K^{(*)} where the D meson is reconstructed from K^+ \pi^-. We also report improved measurements of the branching fractions for the decays B0 --> D_s^{(*)+} \pi^- and anti-{B}0 --> D_s^{(*)+} K^-. Based on these results, we determine the ratio between the amplitudes of the doubly Cabibbo suppressed decay B0 --> D^{(*)+} pi^- and the Cabibbo favored decay B0 --> D^{(*)-} \pi^+. We studied the three-body baryonic B^+ decays, B^+ --> p \anti-Lambda D^{(*)0. The branching fractions as well as the differential branching fractions as a function of the mass of the p anti-Lambda system are presented. These results are compared with theoretical predictions based on the generalized factorization approach. We present a study of the exclusive decays B0 --> D_s^- K0_S pi^+ and B^- \to D_s^+ K^-K^-. We use the D_s^- --> phi pi^-, anti-{K}{}^{*}(892)0 K^- and K0_S K^- decay modes for D_s reconstruction.
        Speaker: Mr. Nikhil Jayant Joshi (Tata Institute of Fundamental Research, Mumbai)
        Slides
      • 16:45
        Precision measurements of Direct CP violation and D0-D0bar mixing at CDF 13m
        The CDF experiment has previously reported evidence for D0-D0bar mixing with a significance equivalent to 3.8 standard deviations based on the time-dependent ratio of the decay rates for D0 --> K^+pi^- and D0 -->K^-pi^+, and charge-conjugates. That measurement was based on an integrated luminosity of 1.5 fb-1 and achieved sensitivities of +-0.35*10-3 and +-7.6*10-3 on the mixing parameters x'^2 and y', respectively. Here we report an updated measurement using the same technique. In addition, we present an analysis that measures CP-violating asymmetries in D*-tagged D0-->pi^+pi^- decays, where any enhancement from the standard model prediction (of the order of 10-3) would be unambiguous evidence for New Physics. A technique combining asymmetries of pi^+pi^-, and K^-pi^+ D0 decays highly suppresses systematic uncertainties due to detector charge-asymmetric efficiencies allowing a measurement limited only by statistical uncertainties. Both measurements are based on a sample corresponding to an integrated luminosity of 5.2 fb-1.
        Speaker: Mark Edward Mattson (Dept of Physics and Astronomy-Wayne State U.)
        Slides
      • 17:00
        D0-D0bar Mixing and CP Asymmetry Measurements at BABAR 13m
        We report on D0 mixing and searches for CP violation in charm meson decays using the large sample of charm anti-charm produced in e+e- annihilation data collected with the BaBar detector at the PEP-II asymmetric-energy B Factory near a center-of-mass energy of 10.58 GeV. A direct measurement of D0-D0bar mixing parameters through a time-dependent amplitude analysis of the Dalitz plots of D^0 --> K^0_S pi^+ pi^- and, for the first time, D^0 --> K^0_S K^+ K^- decays is reported. We measure the mixing parameters x and y and provide the best measurement to date of x. We also report on a search for CP violation in the decay D^+ --> K^0_S pi^+. In the Standard Model, direct CP violation in charm meson decays is predicted to occur at the level of 10^-3 or below. In the decay D^+ --> K^0_S pi^+, a direct CP asymmetry, at the level of 0.33%, is expected from K^0/anti{K}^0 mixing in the final state with any asymmetry significantly different than that being a signature for new physics. In addition, we report on a search for CP violation in Cabibbo suppressed D+ --> K0s K+ pi+ pi- decays and allowed Ds+ --> K0s K+ pi+ pi- decays which is signaled by the difference between the T-odd asymmetries, obtained using triple product correlations, measured for D(s)+ and D(s)- decays.
        Speaker: Matthew Bellis (Stanford University)
        Slides
      • 17:15
        CP violation and mixing in charm decays at Belle 13m
        We have searched for CP violation of charmed mesons in the decays D --> K0_S P, where D denotes D0, D^+ and D_s^+, and P denotes the pseudo-scalar mesons \pi^+, K^+, \pi0, eta and eta^'. No evidence of CP violation in these decays is observed. We have measured the CP asymmetry difference between the Cabibbo suppressed decay D^+ --> phi pi^+ and the Cabibbo favored D_s^+ --> phi pi^+ decays. The measured asymmetry is corrected for the residual asymmetry due to detector effects, and the contributions of both CP and forward-backward asymmetries are determined. We also present a measurement of D0-anti-D0 mixing parameters in three-body D0 decays using a time-dependent Dalitz plot analysis. These results are obtained on a large data sample collected at and near the Upsilon(4S) resonance with the Belle detector operating at the KEKB asymmetric-energy e^+ e^- collider.
        Speaker: Byeong Rok Ko
        Slides
      • 17:30
        Results and prospects for Charm Physics at LHCb 13m
        Precision measurements in charm physics offer a window into a unique sector of potential New Physics interactions. LHCb is poised to become a world leading experiment for charm studies, recording enormous statistics with a detector tailored for flavour physics. The conditions of the 2010-11 run of LHC are especially conducive to the collection of charm events, with a very large data set already attainable this year. First charm results will be shown using data collected at LHCb in pp collisions at 7 TeV center-of-mass energy. The prospects for measurements of CP violation, mixing, and rare decays of charm mesons at LHCb will also be presented.
        Speaker: Ivan Belyaev (Institute for Theoretical and Experimental Physics (ITEP))
        Slides
      • 17:45
        Extracting CP violation and strong phase in D decays by using quantum correlations in psi(3770) -> D0 D0bar -> (V_1V_2)(V_3V_4) and psi(3770) -> D0 D0bar -> (V_1V_2)(K pi) 13m
        The charm quark offers interesting opportunities to cross-check the mechanism of CP violation precisely tested in the strange and beauty sectors. In this paper, we exploit the angular and quantum correlations in the D Dbar pairs produced through the decay of the psi(3770) resonance in a charm factory to investigate CP-violation in two different ways. We build CP-violating observables in psi(3770) -> D Dbar -> (V_1V_2)(V_3 V_4) to isolate specific New Physics effects in the charm sector. We also consider the case of psi(3770) -> D Dbar -> (V_1V_2)(K pi) decays, which provide a new way to measure the strong phase difference delta between Cabibbo-favoured and doubly-Cabibbo suppressed D decays required in the determination of the CKM angle gamma. Neglecting the systematics, we give a first rough estimate of the sensitivities of these measurements at BES-III with an integrated luminosity of 20 fb-1 at psi(3770) peak and at a future Super tau-charm factory with a luminosity of 10^35 cm-2 s-1.
        Speaker: Xian-Wei Kang (IHEP,China)
        Slides
    • 16:15 18:00