Conveners
Parallel: initial state [TH]
- Alfred Mueller (Columbia University)
Parallel: benchmarking [TH+EXP]
- Barbara Jacak (Lawrence Berkeley National Lab. (US))
Parallel: initial state and small systems [EXP]
- Jiangyong Jia (State University of New York (US))
Parallel: azimuthal asymmetries, correlations and fluctuations [TH]
- Hannah Petersen
Parallel: azimuthal asymmetries and UPCs [EXP]
- Brian Cole (Columbia University (US))
Parallel: initial state [TH]
- Nestor Armesto Perez (Universidade de Santiago de Compostela (ES))
Parallel: thermalisation and equilibration [TH]
- Urs Wiedemann (CERN)
Parallel: particle production, hydrodynamics and transport [TH]
- Carlos Pajares Vales (Universidade de Santiago de Compostela (ES))
-
Dr Andry Rakotozafindrabe (CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR))24/05/2016, 14:30Parallel
ALICE is the LHC experiment devoted to the study of heavy-ion collisions. The main purpose of ALICE is to investigate the properties of the deconfined state of nuclear matter, the Quark-Gluon Plasma (QGP). Quarkonium measurements play a crucial role in this investigation. Indeed, heavy quarks are created during the initial stages of the collision, before the QGP formation, and their number is...
Go to contribution page -
Prof. Ian Balitsky (JLab/ODU)24/05/2016, 14:30ParallelI discuss how the rapidity evolution of gluon transverse momentum dependent distribution changes from nonlinear evolution at small x ≪ 1 to linear evolution at moderate x ∼ 1.Go to contribution page
-
Douglas Wertepny (The Ohio State University)24/05/2016, 14:50We calculate the classical single-gluon production amplitude in nucleus--nucleus collisions including the first saturation correction in one of the nuclei (the projectile) while keeping multiple-rescattering (saturation) corrections to all orders in the other nucleus (the target). In our approximation only two nucleons from the projectile nucleus interact: the single-gluon...Go to contribution page
-
Hannu Paukkunen (University of Jyväskylä ; Helsinki Institute of Physics ; Universidade de Santiago de Compostela)24/05/2016, 14:50The notion of centrality in high-energy collisions involving heavy nuclei has lately become a subject of an active discussion. Specifically, the experimental definitions of centrality that have appeared to be well in line with the theoretical expectations in heavy-ion collisions have led to rather weird behaviour when applied to the proton-lead collisions at the LHC and deuteron-gold...Go to contribution page
-
David d'Enterria (CERN)24/05/2016, 15:10ParallelI will present phenomenological studies of top-quark pair production in p-Pb and Pb-Pb collisions at the CERN LHC and at the future circular collider (FCC), obtained with NLO pQCD calculations including nuclear PDFs. In their fully-leptonic decay mode (ttbar->W+W-bbbar->l+l- nunu bbbar), one expects 90 (Pb-Pb) and 300 (p-Pb) top-quarks cleanly tagged per nominal LHC-year, and 47,000--100,000...Go to contribution page
-
Bertrand Ducloue (University of Jyvaskyla)24/05/2016, 15:10ParallelWe discuss single inclusive hadron production from a high energy quark scattering off a strong target color field in the Color Glass Condensate formalism. Recent calculations of this process at the next-to-leading order accuracy have led to negative cross sections at large transverse momenta. We identify the origin of this problem in an oversubtraction of the rapidity divergence into the...Go to contribution page
-
Dennis Vadimovich Perepelitsa (Brookhaven National Laboratory (US))24/05/2016, 15:30Measurements of the particle jets arising from a hard scattering are valuable experimental tools for understanding the physics of small and large systems created in collisions involving nuclei. In small systems, such as in proton- or deuteron-nucleus collisions, they are useful benchmarks of the effects of the nuclear environment on the initial parton densities or the emerging jet energy. In...Go to contribution page
-
Fabio Dominguez (Universidade de Santiago de Compostela)24/05/2016, 15:30Following the recent studies in the effects of next-to-eikonal and next-to-next-to-eikonal propagation in high-energy proton-nucleus collisions, we calculate the corresponding corrections to small-x evolution. These corrections arise explicitly both from non-eikonal propagation of the softer gluon fluctuations, and from emission/absorption of gluons in the projectile wave function while inside...Go to contribution page
-
Michael Lublinsky24/05/2016, 15:50We compute the entanglement entropy of soft gluons in the wave function of a fast moving hadron and discuss its basic properties. We also derive the expression for entropy production in a high energy hadronic collision within the Color Glass formalism. We show that long range rapidity correlations give negative contribution to the production entropy. We calculate the (naturally defined)...Go to contribution page
-
Kaya Tatar (Massachusetts Inst. of Technology (US))24/05/2016, 15:50Parallel
This talk summarizes the latest results on jets in pp, pPb and PbPb collisions from the CMS collaboration
Go to contribution page -
Guillaume Beuf (ECT* Trento)24/05/2016, 16:10Deep Inelastic Scattering (DIS) is the cleanest tool available to probe the content of a fast proton or nucleus. In the regime of low Bjorken x, one enters in the nonlinear regime of gluon saturation, where the gluons are better described as a strong coherent semi-classical field than as a collection of quasi on-shell partons. Hence, that regime lies outside the validity range of...Go to contribution page
-
Miguel Ignacio Arratia Munoz (University of Cambridge (GB))24/05/2016, 16:10Parallel
-
Rajeev Bhalerao (TIFR)24/05/2016, 17:00We extend the recently presented Principal Component Analysis (PCA) method to reduce the nonflow effects present in the two-particle correlation data. We illustrate this technique by applying it to simulated pseudorapidity correlation data obtained with A Multi-Phase Transport (AMPT) model for Pb-Pb collisions at the LHC energy 2.76 TeV. Measurable subleading modes are seen in...Go to contribution page
-
Alvaro Dosil Suarez (Universidade de Santiago de Compostela (ES))24/05/2016, 17:00ParallelThe productions of prompt $D^0$ mesons in proton-lead collisions in the forward and backward configurations were studied. The data are collected with the LHCb detector with at a centre-of-mass energy of 5TeV. The integrated cross-section is measured to be 237±1±15mb (259±3±19mb) for the forward (backward) rapidity range 1.5 < y< 4 (5 < y < 2.5), in the pT range 0 < pT < 8 GeV/c. Nuclear...Go to contribution page
-
Austin Alan Baty (Massachusetts Inst. of Technology (US))24/05/2016, 17:20ParallelDuring the fall of 2015, LHC provided high-luminosity PbPb and pp collision data at 5 TeV collision energy per nucleon pair, allowing for precision measurements of hot-medium effects. The measured charged particle spectra from the two collision systems are presented up to approximately 100 GeV of transverse momentum, for charged particles produced in the central rapidity region. The nuclear...Go to contribution page
-
Prof. Carlos Pajares (University santiago de Compostela)24/05/2016, 17:20ParallelIt is shown that the RHIC and LHC experimental data on v2(pt) and v3(pt) for all centralities satisfy an scaling law.All data lie on a curve that is obtained assuming are proportional to the energy loss of a produced parton interacting with the color field of the rest of produced partons.It is studied the extensión of the scaling to v4 and v5Go to contribution page
-
Dr Xiangrong Zhu (Peking University)24/05/2016, 17:40Flow measurements in p+Pb collisions at $\sqrt{s_{\rm NN}}$=5.02 TeV have indicated the development of collective flow in the small systems created at the LHC. Using the ultrarelativistic quantum molecular dynamics (UrQMD) model, we investigate the azimuthal correlations in p+Pb collisions at $\sqrt{s_{\rm NN}}$=5.02 TeV with two- and four-particle cumulants. Our calculations indicate that...Go to contribution page
-
Michael Ryan Clark (Columbia University (US))24/05/2016, 17:40Parallel
Bose-Einstein correlations between identified charged pions are measured for $p$+Pb
Go to contribution page
collisions at $\sqrt{s_{\mathrm{NN}}}=5.02~\mathrm{TeV}$ with the ATLAS detector with
a total integrated luminosity of $28~\inb$. Pions are identified using ionization
energy loss measured in the pixel detector. Two-particle correlation functions and
the extracted source radii are presented as a function of... -
Valentina Zaccolo (University of Copenhagen (DK))24/05/2016, 18:00ParallelAn overview of the measured pseudorapidity densities and multiplicity distributions at the LHC's Run 1 and 2 energies will be presented for pp, p-Pb and Pb-Pb systems. The ALICE results are shown for central pseudorapidities and, if available, over a wider pseudorapidity range (-3.4 < η < 5.0). The measurement of the inclusive charged-particle production in high-energy interactions is a...Go to contribution page
-
Wojciech Broniowski (IFJ PAN)24/05/2016, 18:00Parallel
Rapidity correlations are analyzed in a simple model, where in the initial stage multiple sources, extended in space-time rapidity, are formed. We show how the varying longitudinal extent of the sources generates correlations in the initial entropy deposition, which later contribute to the observed correlations in hadron production. Our analytic analysis allows to understand their structure...
Go to contribution page -
Piotr Bozek (AGH University of Science and Technology)24/05/2016, 18:20Parallel
We present results of a 3+1 dimensional hydrodynamic model for flow correlations in pseudorapidity. The method can be used to unfold the correlations in the initial fireball at different space-time rapidities.
Go to contribution page
We discuss possible mechanism of generating initial correlations in rapidity, both with nucleon and parton degrees of freedom. Particular sensitivity to the initial correlations is... -
Dieter Roehrich (University of Bergen (NO))24/05/2016, 18:20on the behalf of the ALICE‐FoCal Collaboration Direct photon production at forward rapidity is a promising probe for the gluon content of protons and nuclei at small *x*. In particular, the measurement of the nuclear modification factor for direct photons in p–A collisions at the LHC is a crucial test for gluon saturation. A new forward calorimeter (FoCal) is proposed as an upgrade to the...Go to contribution page
-
Fiorella Fionda (Universita e INFN (IT))24/05/2016, 18:40Parallel
Recent measurements in high-multiplicity proton-proton (pp) and proton-lead (p-Pb)
collisions show several features that are similar to those observed in heavy-ion collisions. In this respect strangeness production may provide a valuable investigative
tool.Baryon-to-meson ratios, such as Λ/KS0, have been measured
Go to contribution page
differentially in pT and show an evolution... -
Wojciech Florkowski (Institute of nuclear Physics, Krakow)24/05/2016, 18:40Dynamic features of a plasma consisting of gluons whose infrared dynamics is improved by the Gribov-Zwanziger quantization are presented. This approach includes important features of color confinement which set the plasma apart from conventional quasiparticle systems in several aspects [1]. We obtain explicit expressions for the transport coefficients $\eta$ and $\zeta$ (shear and bulk...Go to contribution page
-
Elena Petreska (Universidade de Santiago de Compostela/ Ecole Polytechnique)25/05/2016, 14:00Forward rapidity observables in high-energy proton-nucleus collisions are optimal for probing gluon saturation effects in the target nucleus. We study two small-x observables at forward rapidity: dijet azimuthal correlations in proton-nucleus collisions, and induced coherent spectrum associated with single parton scattering. Both observables are first analyzed from a CGC (color glass...Go to contribution page
-
Peter Alan Steinberg (Brookhaven National Laboratory (US))25/05/2016, 14:00Parallel(speaker known later) The large equivalent-photon fluxes accompanying Pb ion beams at the LHC initiate photon-photon and photo-nuclear interactions which dominate when the colliding nuclei have large impact parameter (ultra-peripheral collisions). These electromagnetically-induced processes are sensitive to the nuclear wave-function and in particular the nuclear modifications of the nucleon...Go to contribution page
-
Jesus Guillermo Contreras Nuno (Czech Technical University (CZ))25/05/2016, 14:20ParallelThe strong electromagnetic fields generated by ultra-relativistic heavy ions offer the possibility to study photoproduction processes at the LHC. In so called ultra-peripheral collisions (UPC), when the impact parameter of the incoming hadrons is larger than the sum of their radii, hadronic processes are strongly suppressed and only electromagnetic interactions remain. ALICE has measured the...Go to contribution page
-
Alba Soto Ontoso (UGR)25/05/2016, 14:20The initial energy deposited in heavy ion collisions depends on the initial size and shape of the interaction area. Therefore, a precise picture of the proton in impact parameter space is needed in order to correctly interpret the recent and forthcoming RHIC and LHC results in pp,pA and AA collisions. In this talk, I shall present a comparative study of the impact parameter profile of the...Go to contribution page
-
Jamal Jalilian-Marian (Baruch College)25/05/2016, 14:40we calculate the cross section for production of three partons in scattering of (real or virtual) photons on a proton or nucleus target at high energy using the Color Glass Condensate formalism. We investigate the azimuthal angular correlations among the three produced partons and show that they are a sensitive probe of saturation dynamics. We outline how this cross section can be used to...Go to contribution page
-
Dipanwita Dutta (Bhabha Atomic Research Centre (IN))25/05/2016, 14:40ParallelUltraperipheral collisions (UPCs) of heavy ions or hadrons involve long range electromagnetic interactions at impact parameters larger than sum of their radii where hadronic interaction is largely suppressed and the exchanged photon materializes into qq(bar) bound state after interacting with the gluonic field of the target proton or ion. Photoproduction of heavy vector mesons (J/psi, Upsilon)...Go to contribution page
-
Quan Wang (University of Kansas (US))25/05/2016, 15:00Parallel
Previous measurements have demonstrated the collective nature of multiparticle correlations in high-multiplicity pPb collisions at the LHC. This collectivity, while consistent with a hydrodynamic flow origin, can also be interpreted in terms of initial state effects arising from gluon saturation. To investigate the detailed properties of this collectivity, differential Fourier coefficients in...
Go to contribution page -
Amir Rezaeian (Universidad Tecnica Federico Santa Maria)25/05/2016, 15:00I will present the recent analysis of the photon-jet correlations in the Color Glass Condensate (CGC) framework in proton-proton and proton-nucleus collisions at RHIC and the LHC. I show that photon-jet correlations exhibit long-range in rapidity ridge-like structure at low transverse momenta of the produced jet and photon in high-multiplicity events. These features are strikingly similar to...Go to contribution page
-
Krzysztof Kutak (Instytut Fizyki Jadrowej Polskiej Akademii Nauk)25/05/2016, 15:20I would like to report on first study of 4-jet production in a complete high-energy factorization (HEF) framework. The results include contributions from both single-parton scattering (SPS) and double-parton scattering (DPS). The calculations are performed for kinematical situations relevant for two experimental measurements (ATLAS and CMS) at the LHC. We compare our results to those reported...Go to contribution page
-
Soumya Mohapatra (Columbia University (US))25/05/2016, 15:20Parallel(speaker known later) Measurements of the nuclear modification factor ($R_{\mathrm{AA}}$) and the elliptic flow ($v_{2}$) of muons from heavy-quark decays in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}$=2.76 TeV from the ATLAS experiment are presented. The measurements are done over the $p_{\mathrm{T}}$ range of 4-14~GeV and over the centrality range of (0-60)%. A significance elliptic flow...Go to contribution page
-
Takafumi Niida (University of Tsukuba (JP))25/05/2016, 15:40At the early stages of non-central heavy-ion collisions, a strong magnetic field perpendicular to the reaction plane is created. In asymmetric Cu+Au collisions, due to the difference in the number of spectators, not only the magnetic field but also a strong electric field (E-field) would be created along the reaction plane and pointing from the Au-nucleus to Cu-nucleus. The lifetime of the...Go to contribution page
-
Dr Heikki Mäntysaari (Brookhaven National Laboratory)25/05/2016, 15:40Exclusive vector meson production can be used to directly probe the gluon density of a hadron. Measuring the cross section differentially in momentum transfer t makes it possible to determine the transverse density profile (via coherent diffraction) and density fluctuations (incoherent diffraction) of the target hadron. This knowledge on the geometric fluctuations of the proton is particularly...Go to contribution page
-
Scott Moreland (Duke University)25/05/2016, 16:30Parallel
Initial state models translate the spacetime overlap of nuclear density between projectile and target nuclei to generate profiles of entropy (or energy) at the QGP thermalization time which are subsequently evolved by relativistic viscous fluid dynamics. Historically, these initial conditions were generated by one of two means: either from a two-component Glauber ansatz which asserts an...
Go to contribution page -
Dr Risto Paatelainen (University of Santiago de Compostela)25/05/2016, 16:30We present the recent results from the event-by-event next-to-leading order perturbative-QCD + saturation + viscous hydrodynamics (EKRT) model [1,2]. In particular, we show the computed predictions for the centrality dependence of charged hadron multiplicity, flow coefficients of the azimuthal-angle asymmetries and correlations of event-plane angles in 5.02 TeV Pb+Pb collisions at the LHC. The...Go to contribution page
-
Stefan Floerchinger (CERN)25/05/2016, 16:50ParallelBaryon number density perturbations offer a possible route to experimentally measure baryon number susceptibilities and heat conductivity of the quark gluon plasma. We study the fluid dynamical evolution of local and event-by-event fluctuations of baryon number density, flow velocity, and energy density on top of a (generalized) Bjorken expansion. To that end we use a background-fluctuation...Go to contribution page
-
Dr Radoslaw Ryblewski (Institute of Nuclear Physics PAN)25/05/2016, 16:50ParallelDetailed study of thermalization of the momentum spectra of partons produced via decays of the color flux tubes due to the Schwinger tunneling mechanism is presented. The collisions between particles are included in the relaxation time approximation specified by different values of the shear viscosity to entropy density ratio. At first we show that, to a good approximation, the...Go to contribution page
-
David Mueller (Vienna University of Technology)25/05/2016, 17:10
We present our work on the simulation of the quark-gluon-plasma using the colored particle-in-cell (CPIC) method. CPIC is a generalization of particle-in-cell simulations - commonly used in plasma physics - to real-time non-abelian lattice gauge theories. Using this method we are able to model the early time dynamics of heavy-ion collisions in the laboratory frame in 3+1 dimensions. In...
Go to contribution page -
Yan Zhu (University of Jyvaskyla)25/05/2016, 17:10ParallelEarly stages before hydrodynamization in heavy ion collision is studied by numerically solving a 2+1D effective kinetic theory of weak coupling QCD under longitudinal expansion. We find agreement with viscous hydrodynamics and classical Yang-Mills simulations in the regimes where they are applicable. By choosing initial conditions that are motivated by color-glass-condensate framework we find...Go to contribution page
-
Prithwish Tribedy (Brookhaven National Lab)25/05/2016, 17:30We compute gluon production from the Color Glass Condensate based IP-Glasma model and perform hadronization with PYTHIA's Lund string fragmentation to study bulk observables in small colliding systems at the LHC. In particular we study high multiplicity events in which observations are often attributed to final state collective effects. We find that our alternative description, based largely...Go to contribution page
-
Aleksas Mazeliauskas (Stony Brook University)25/05/2016, 17:30We use effective kinetic theory, accurate at weak coupling, to simulate the pre-equilibrium evolution of transverse energy and flow perturbations in heavy-ion collisions. We provide a Green function which propagates the initial perturbations to the energy-momentum tensor at a time when hydrodynamics becomes applicable. With this map, the complete pre-thermal evolution from saturated nuclei to...Go to contribution page
-
Roy Lacey (Stony Brook University)25/05/2016, 17:50ParallelThe question of whether there are fundamental differences between soft particle production in small systems (p+p, p+A, etc) and large systems (A+A(B)) is deemed by many to be an unsettled issue. The explicit role of the initial state for these systems is similarly predisposed. I will demonstrate that the scaling properties of the pseudorapidity density (dN/deta) for p+p, p+A and A+A(B)...Go to contribution page
-
Wilke van der Schee (MIT)25/05/2016, 17:50In the past years much progress has been made to understand the initial stage of heavy ion collisions at very strong coupling. I will briefly review this approach, which in particular led to a full 3+1D simulation of off-central collisions using the MUSIC hydrodynamic code. I will report on progress on collisions with a conserved charge [1], which will be relevant for the beam energy scan....Go to contribution page
-
Vladimir Kovalenko (St. Petersburg State University (RU))25/05/2016, 18:10Parallel
Demonstrated that the investigations of the forward-backward correlations between intensive observables enable to obtain more clear signal about the initial stage of hadronic interaction, e.g. about the process of string fusion, compared to usual forward-backward multiplicity correlations. As an example the correlation between mean-event transverse momenta of charged particles in separated...
Go to contribution page -
maximilian attems (University of Barcelona)25/05/2016, 18:10Ever since fast hydrodynamization has been observed in heavy ion collisions at RHIC, attempts to understand this feature of the very early non-equilbrium stage have been made. We use the gauge/string duality to model the evolution of strongly coupled Quark-Gluon plasma in a non-conformal gauge theory. The non-trivial equation of state and the presence of a time dependent bulk viscosity change...Go to contribution page
-
Prof. Jitesh Bhatt (Physical Research Laboratory)25/05/2016, 18:30We study the chiral-imbalance and the Weibel instabilities in presence of the quantum anomaly using the Berry-curvature modified kinetic equation. We argue that in many realistic situations, e.g. relativistic heavy-ion collisions, both the instabilities can occur simultaneously. The Weibel instability depends on the momentum anisotropy parameter ξ and the angle (θn) between the propagation...Go to contribution page
-
Cheuk-Yin Wong (Oak Ridge National Laboratory)25/05/2016, 18:30ParallelThe initial conditions in high-energy pp collisions can be well examined from the momentum distributions of both jets and hadrons in these collisions, as they provide relevant information on the collision mechanism and the initial properties of the produced medium. It was found recently that in pp collisions at the LHC, the hadron transverse momentum distributions at central rapidity...Go to contribution page