Quark Matter 2015 - XXV International Conference on Ultrarelativistic Nucleus-Nucleus Collisions

Session

Initial State Physics and Approach to Equilibrium I

28-011

28 Sept 2015, 14:30

Kobe, Fashion Mart, Japan

Conveners

Initial State Physics and Approach to Equilibrium I

• Sangyong Jeon (McGill University (CA))

22. Re-weighting at the LHC: the p-Pb data impact

Maria Zurita (Universidade de Santiago de Compostela)

28/09/2015, 14:30

Initial State Physics and Approach to Equilibrium

Contributed talk

One of the goals of the proton-lead run at the LHC is to produce a benchmark for heavy-ion collisions. Preliminary analyzes hint that nPDFs fail to give a proper description for certain observables. Here we present a full study of the compatibility between current sets of initial state nuclear distributions and data from the LHC p-Pb run. By means of reweighting techniques [1,2] we give a...

396. Charged-Particle Multiplicity Distributions over Wide Pseudorapidity Range in Proton-Proton Collisions with ALICE

Valentina Zaccolo (University of Copenhagen (DK))

28/09/2015, 14:50

Initial State Physics and Approach to Equilibrium

Contributed talk

The distribution of charged particles produced in high energy pp collisions, $P(N_{ch})$, as a function of $N_{ch}$, is sensitive to the number of collisions between quarks and gluons contained in the colliding systems and to the mechanisms underlying particle production. In particular, it is a good probe for the saturation density of gluons in the colliding hadrons. For the first time,...

689. Centrality and pseudorapidity dependence of transverse energy flow in pPb collisions at 5.02 TeV with CMS

Michael Murray (University of Kansas (US))

28/09/2015, 15:10

Initial State Physics and Approach to Equilibrium

Contributed talk

The CMS Collaboration has measured the pseudorapidity and centrality dependence $dE{T}/d\eta$ for 5.02 TeV pPb collisions over 10 units of pseudo-rapidity. This was carried out in a systematic way by measuring centrality using different experimental definitions. As the centrality increases the mean pseudorapidity moves backwards and the $1/N dE_{T}/d\eta$ distribution widens. For the most...

319. Initial state from holography

Wilke van der Schee (MIT)

28/09/2015, 15:30

Initial State Physics and Approach to Equilibrium

Contributed talk

Through holography we can collide arbitrary lumps of energy in strongly coupled gauge theories, where we assume transverse gradients are small in the very first moments of the collision. This can be applied to off-central collisions and subsequently evolved using the MUSIC 3+1D hydrodynamic code. This allows us to compare to experimental observables, where we focus on the multiplicity and...

159. Initial state azimuthal anisotropies in small collision systems

Tuomas Lappi (University of Jyvaskyla)

28/09/2015, 15:50

Initial State Physics and Approach to Equilibrium

Contributed talk

Recent experimental results have revealed a surprisingly rich structure of multiparticle azimuthal correlations in high energy proton-nucleus collisions. Final state collective effects can be responsible for many of the observed effects, but it has recently been shown that a part of these correlations are present already in the wavefunctions of the colliding particles. A domain structure at...

625. Azimuthal Harmonics at RHIC and LHC energies: Competition between Initial State Bremsstrahlung and Final State Hydrodynamics

Peter Levai (Hungarian Academy of Sciences (HU))

28/09/2015, 16:10

Initial State Physics and Approach to Equilibrium

Contributed talk

Recent azimuthal correlation data from d+Au and Au+Au collisions at RHIC energies and cumulant azimuthal harmonics in p+Pb and PbPb at LHC energies display very similar size and characteristics challenging the uniqueness of local equilibrium hydrodynamical interpretation of these data. We show that in p+A collisions the azimuthal harmonics arising from initial-state non-abelian interference...