Anisotropic flow in Pb+Pb collisions at LHC from the quark gluon string model with parton rearrangement

TL;DR

This paper predicts the pseudorapidity dependence of azimuthal anisotropy parameters v_1 and v_2 in Pb+Pb collisions at LHC energies using an extended quark gluon string model with parton rearrangement, comparing central and semi-peripheral collisions.

Contribution

It introduces an extension of the quark gluon string model incorporating parton rearrangement to predict flow parameters at LHC energies.

Findings

v_1(eta) shows small normal flow alignment at LHC.

v_2(eta) shape similar to RHIC, magnitude 10-20% higher.

Hydrodynamical limit likely reached at LHC.

Abstract

We present predictions for the pseudorapidity dependence of the azimuthal anisotropy parameters v_1 and v_2 of baryons and inclusive charged hadrons in Pb+Pb collisions at a LHC energy of sqrt(s) = 5.5 TeV applying a microscopic transport model, namely the quark gluon string model (QGSM) which has been recently extended for parton rearrangement and fusion processes. Pb+Pb collisions with impact parameters b = 2.3 fm and b = 8 fm have been simulated in order to investigate additionally the difference between central and semiperipheral configurations. In contrast to v_1(eta) at RHIC, the directed flow of charged hadrons shows a small normal flow alignment. The elliptic flow v_2(eta) turns out to be rather similar in shape for RHIC and LHC conditions, the magnitude however increases about 10-20 % at the LHC, leading to the conclusion that the hydrodynamical limit will be reached.