Collective Flow and Mach Cones with transport

I Bouras,J Uphoff,C Greiner,O Fochler,A El,C Wesp,Z Xu,F Reining

doi:10.1051/epjconf/20111307001

I Bouras, J Uphoff + Show 6 more

Open Access

https://doi.org/10.1051/epjconf/20111307001

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Abstract

Fast thermalization and a strong build up of elliptic flow of QCD matter were investigated within the pQCD based 3+1 dimensional parton transport model BAMPS including bremsstrahlung $2 \leftrightarrow 3$ processes. Within the same framework quenching of gluonic jets in Au+Au collisions at RHIC can be understood. The development of conical structure by gluonic jets is investigated in a static box for the regimes of small and large dissipation. Furthermore we demonstrate two different approaches to extract the shear viscosity coefficient $\eta$ from a microscopical picture.

Highlights

The large value of the elliptic flow v2 measured in experiments at the Relativisitc Heavy Ion collider (RHIC)[1,2,3] suggests, that in the hot and dense fireball equilibration of quarks and gluons occurs on a very short time scale ≤ 1 fm/c
This quenching of jets is commonly attributed to energy loss on the partonic level as the hard partons produced in initial interactions are bound to traverse the quark gluon plasma (QGP) created in the early stages of heavy-ion collisions (HIC)
BAMPS has been recently applied to calculate elliptic flow and jet quenching at RHIC energies [12] for the first time in a consistent and fully perturbative QCD (pQCD)–based microscopic transport model

Summary

Introduction

The large value of the elliptic flow v2 measured in experiments at the Relativisitc Heavy Ion collider (RHIC)[1,2,3] suggests, that in the hot and dense fireball equilibration of quarks and gluons occurs on a very short time scale ≤ 1 fm/c. BAMPS has been recently applied to calculate elliptic flow and jet quenching at RHIC energies [12] for the first time in a consistent and fully pQCD–based microscopic transport model Both key observables could be addressed on the partonic level within a common setup. To complement the investigations of RAA at a non–zero impact parameter b = 7 GeV, we have computed the elliptic flow parameter v2 for gluons at the same impact parameter and extended the range in transverse momentum up to roughly pT ≈ 10 GeV, see left panel of Fig. 2 For this a critical energy density εc = 0.6 GeV/fm has been used, in order to be comparable to previous calculations of the elliptic flow within BAMPS. This behavior is in good qualitative agreement with recent RHIC data [23] that for charged hadrons shows v2 to be rising up to v2 ≈ 0.15 at pT ≈ 3 GeV followed by a slight decrease

Transition from ideal to dissipative Mach Cones

Extraction of shear viscosity from microscopic theory