A combined model for pseudorapidity distributions in Cu-Cu collisions at BNL-RHIC energies

TL;DR

This paper presents a combined model incorporating leading particles and a unified hydrodynamics approach to accurately describe pseudorapidity distributions in Cu-Cu collisions at BNL-RHIC energies, matching experimental data.

Contribution

The paper introduces a novel combined model that integrates Gaussian leading particle distributions with a unified hydrodynamics framework for the first time.

Findings

Model predictions agree well with experimental data.

Unified hydrodynamics effectively describes hot and dense matter expansion.

Combined approach improves understanding of particle production in collisions.

Abstract

The charged particles produced in nucleus-nucleus collisions come from leading particles and those frozen out from the hot and dense matter created in collisions. The leading particles are conventionally supposed having Gaussian rapidity distributions normalized to the number of participants. The hot and dense matter is assumed to expand according to the unified hydrodynamics, a hydro model which unifies the features of Landau and Hwa-Bjorken model, and freeze out into charged particles from a space-like hypersurface with a proper time of Tau_FO . The rapidity distribution of this part of charged particles can be derived out analytically. The combined contribution from both leading particles and unified hydrodynamics is then compared against the experimental data performed by BNL-RHIC-PHOBOS Collaboration in different centrality Cu-Cu collisions at sqrt(s_NN)=200 and 62.4 GeV, respectively. The model predictions are in well consistent with experimental measurements.