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, 14:30
Parallel
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...
Prof.
Ian Balitsky
(JLab/ODU)
24/05/2016, 14:30
Parallel
I 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.
Douglas Wertepny
(The Ohio State University)
24/05/2016, 14:50
We 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...
Hannu Paukkunen
(University of Jyväskylä ; Helsinki Institute of Physics ; Universidade de Santiago de Compostela)
24/05/2016, 14:50
The 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...
David d'Enterria
(CERN)
24/05/2016, 15:10
Parallel
I 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...
Bertrand Ducloue
(University of Jyvaskyla)
24/05/2016, 15:10
Parallel
We 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...
Dennis Vadimovich Perepelitsa
(Brookhaven National Laboratory (US))
24/05/2016, 15:30
Measurements 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...
Fabio Dominguez
(Universidade de Santiago de Compostela)
24/05/2016, 15:30
Following 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...
Kaya Tatar
(Massachusetts Inst. of Technology (US))
24/05/2016, 15:50
Parallel
This talk summarizes the latest results on jets in pp, pPb and PbPb collisions from the CMS collaboration
Guillaume Beuf
(ECT* Trento)
24/05/2016, 16:10
Deep 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...
Miguel Ignacio Arratia Munoz
(University of Cambridge (GB))
24/05/2016, 16:10
Parallel
Alvaro Dosil Suarez
(Universidade de Santiago de Compostela (ES))
24/05/2016, 17:00
Parallel
The 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...
Austin Alan Baty
(Massachusetts Inst. of Technology (US))
24/05/2016, 17:20
Parallel
During 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...
Prof.
Carlos Pajares
(University santiago de Compostela)
24/05/2016, 17:20
Parallel
It 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 v5
Dr
Xiangrong Zhu
(Peking University)
24/05/2016, 17:40
Flow 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...
Michael Ryan Clark
(Columbia University (US))
24/05/2016, 17:40
Parallel
Bose-Einstein correlations between identified charged pions are measured for $p$+Pb
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, 18:00
Parallel
An 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...
Wojciech Broniowski
(IFJ PAN)
24/05/2016, 18:00
Parallel
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...
Piotr Bozek
(AGH University of Science and Technology)
24/05/2016, 18:20
Parallel
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.
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, 18:20
on 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...
Fiorella Fionda
(Universita e INFN (IT))
24/05/2016, 18:40
Parallel
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
differentially in pT and show an evolution...
Wojciech Florkowski
(Institute of nuclear Physics, Krakow)
24/05/2016, 18:40
Dynamic 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...
Elena Petreska
(Universidade de Santiago de Compostela/ Ecole Polytechnique)
25/05/2016, 14:00
Forward 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...
Peter Alan Steinberg
(Brookhaven National Laboratory (US))
25/05/2016, 14:00
Parallel
(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...
Jesus Guillermo Contreras Nuno
(Czech Technical University (CZ))
25/05/2016, 14:20
Parallel
The 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...
Jamal Jalilian-Marian
(Baruch College)
25/05/2016, 14:40
we 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...
Dipanwita Dutta
(Bhabha Atomic Research Centre (IN))
25/05/2016, 14:40
Parallel
Ultraperipheral 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)...
Quan Wang
(University of Kansas (US))
25/05/2016, 15:00
Parallel
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...
Amir Rezaeian
(Universidad Tecnica Federico Santa Maria)
25/05/2016, 15:00
I 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...
Krzysztof Kutak
(Instytut Fizyki Jadrowej Polskiej Akademii Nauk)
25/05/2016, 15:20
I 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...
Soumya Mohapatra
(Columbia University (US))
25/05/2016, 15:20
Parallel
(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...
Takafumi Niida
(University of Tsukuba (JP))
25/05/2016, 15:40
At 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...
Dr
Heikki Mäntysaari
(Brookhaven National Laboratory)
25/05/2016, 15:40
Exclusive 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...
Scott Moreland
(Duke University)
25/05/2016, 16:30
Parallel
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...
Dr
Risto Paatelainen
(University of Santiago de Compostela)
25/05/2016, 16:30
We 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...
Stefan Floerchinger
(CERN)
25/05/2016, 16:50
Parallel
Baryon 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...
Dr
Radoslaw Ryblewski
(Institute of Nuclear Physics PAN)
25/05/2016, 16:50
Parallel
Detailed 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...
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...
Yan Zhu
(University of Jyvaskyla)
25/05/2016, 17:10
Parallel
Early 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...
Prithwish Tribedy
(Brookhaven National Lab)
25/05/2016, 17:30
We 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...
Aleksas Mazeliauskas
(Stony Brook University)
25/05/2016, 17:30
We 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...
Roy Lacey
(Stony Brook University)
25/05/2016, 17:50
Parallel
The 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)...
Wilke van der Schee
(MIT)
25/05/2016, 17:50
In 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....
Vladimir Kovalenko
(St. Petersburg State University (RU))
25/05/2016, 18:10
Parallel
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...
maximilian attems
(University of Barcelona)
25/05/2016, 18:10
Ever 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...
Prof.
Jitesh Bhatt
(Physical Research Laboratory)
25/05/2016, 18:30
We 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...
Cheuk-Yin Wong
(Oak Ridge National Laboratory)
25/05/2016, 18:30
Parallel
The 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...
