System size dependence of freeze-out properties at RHIC

TL;DR

This study analyzes how the size of the colliding system at RHIC influences the freeze-out properties of particles, using experimental data from Cu+Cu, Au+Au, and p+p collisions to enhance understanding of QCD phase transitions.

Contribution

It provides a systematic analysis of freeze-out parameters across different system sizes and energies using blast-wave and statistical models, highlighting the role of collision geometry.

Findings

Freeze-out parameters vary with system size and collision energy.

Collision geometry significantly affects freeze-out properties.

Results contribute to understanding QCD phase diagram.

Abstract

The STAR experiment at RHIC has measured identified pi(+/-), K(+/-) and p(pbar) spectra and ratios from sqrt(s_NN) = 62.4 and 200 GeV Cu+Cu collisions. The new Cu+Cu results are studied with hydro-motivated blast-wave and statistical model frameworks in order to characterize the freeze-out properties of this system. Along with measurements from Au+Au and p+p collisions, the obtained freeze-out parameters are discussed as a function of collision energy, system size, centrality and inferred energy density. This multi-dimensional systematic study reveals the importance of the collision geometry and furthers our understanding of the QCD phases.