Viscous Hydrodynamic Description of the Pseudorapidity Density and Energy Density Estimation for Pb+Pb and Xe+Xe Collisions at the LHC

Xiong-Tao Gong,Ze-Fang Jiang,C B Yang,Duan She

doi:10.3390/universe5050112

Abstract

Based on the analytical solution of accelerating relativistic viscous fluid hydrodynamics and Buda–Lund model, the pseudorapidity distributions of the most central Pb+Pb and Xe+Xe collisions are presented. Inspired by the CNC model, a modified energy density estimation formula is presented to investigate the dependence of the initial energy density estimation on the viscous effect. This new energy density estimation formula shows that the bulk energy is deposited to the neighboring fluid cells in the presence of the shear viscosity and bulk viscosity. In contrast to the well-known CNC energy density estimation formula, a 4.9% enhancement of the estimated energy density at the LHC kinematics is shown.

Highlights

Relativistic hydrodynamics is one of the most useful tools to investigate the space-time evolution and transport properties of the quark-gluon plasma (QGP) produced in high-energy heavy-ion collisions [1,2]
Analytical solutions with simplified initial conditions are useful in understanding the properties of this strongly coupled quantum chromodynamics (QCD)
The basic formulation of relativistic hydrodynamics can be found in the literature [20,21]

Summary

Introduction

Relativistic hydrodynamics is one of the most useful tools to investigate the space-time evolution and transport properties of the quark-gluon plasma (QGP) produced in high-energy heavy-ion collisions [1,2]. In this paper, based on the well-known Buda–Lund model [14], an analytical solution of accelerating viscous relativistic hydrodynamics [15] is applied to investigate the final hadron pseudorapidity distribution and the energy density estimation. S NN = 5.44 TeV Xe+Xe collisions [18] are presented Based on this hydrodynamic model with longitudinal accelerating flow effect, the longitudinal acceleration parameters (λ) are extracted from those experimental systems. Based on the CNC (Csörgő, Nagy, Csanád.) energy density estimation model [8,9] and its new results [10,19], a possible relationship between the energy density estimation and viscosity effect is investigated. This paper is organized as follows: in Section 2, we describe the hydrodynamic solutions and calculate the pseudorapidity densities.

Pseudorapidity Distribution from Hydrodynamics

Relationship between the Energy Density Estimation and Viscous Effect

Conclusions and Discussion