Thermal-model-based characterization of heavy-ion-collision systems at chemical freeze-out

TL;DR

This paper explores how the hadronic spectrum influences thermal model analyses of chemical freeze-out in heavy-ion collisions, examining the effects of resonance inclusion and separate freeze-out conditions on model parameters.

Contribution

It introduces a detailed study of the impact of varying hadronic resonances and separate freeze-out scenarios on thermal model results in heavy-ion collisions.

Findings

Resonance spectrum significantly affects freeze-out parameter estimates.

Separate freeze-out for strange and non-strange particles alters temperature fits.

Including more resonances changes the predicted particle yields.

Abstract

We investigate the chemical freeze-out in heavy-ion collisions (HICs) and the impact of the hadronic spectrum on thermal model analyses. Detailed knowledge of the hadronic spectrum is still an open question, which has phenomenological consequences on the study of HICs. By varying the number of resonances included in Hadron Resonance Gas (HRG) Model calculations, we can shed light on which particles may be produced. Furthermore, we study the influence of the number of states on the so-called two flavor freeze-out scenario, in which strange and light particles can freeze-out separately. We consider results for the chemical freeze-out parameters obtained from thermal model fits and from calculating net-particle fluctuations. We will show the effect of using one global temperature to fit all particles and alternatively, allowing particles with and without strange quarks to freeze-out separately.