Thermal analysis of particle ratios and p_T spectra at RHIC

TL;DR

This paper uses a thermal model to analyze particle ratios and transverse momentum spectra at RHIC, determining freeze-out temperature and chemical potential, and accounting for resonance decays to explain spectral features.

Contribution

It provides a detailed thermal model analysis of RHIC data, including resonance decay effects on spectra and precise freeze-out parameters.

Findings

Freeze-out temperature T_chem = 165 ± 7 MeV

Baryon chemical potential μ^B_chem = 41 ± 5 MeV

Resonance decays cause a 35-40 MeV cooling of spectra

Abstract

The thermal model of particle production is used to analyze the particle ratios and the p_T spectra measured recently at RHIC. Our fit of the particle ratios yields the temperature at the chemical freeze-out T_chem = 165 +- 7 MeV with the corresponding baryon chemical potential mu^B_chem = 41 +- 5 MeV. The quality of the fit shows that the model works well for RHIC. The p_T spectra are evaluated in an approach which takes into account the modifications of the initial thermal distributions by the secondary decays of resonances. All two- and three-body decays are included. This leads to an effective ``cooling'' of the spectra in the data region by about 35-40 MeV. We find that the pion spectrum is characterized by the inverse slope which agrees well with the value inferred from the RHIC data.