English

Spectra and radial flow at RHIC with Tsallis statistics in a Blast-Wave description

Nuclear Experiment 2014-11-18 v2

Abstract

We have implemented the Tsallis statistics in a Blast-Wave model and applied it to mid-rapidity transverse-momentum spectra of identified particles measured at RHIC. This new Tsallis Blast-Wave function fits the RHIC data very well for pT<p_T<3 GeV/cc. We observed that the collective flow velocity starts from zero in p+p and peripheral Au+Au collisions growing to 0.470 ±\pm 0.009(cc) in central Au+Au collisions. The (q1)(q-1) parameter, which characterizes the degree of non-equilibrium in a system, changes from 0.100±0.0030.100\pm0.003 in p+p to 0.015±0.0050.015\pm0.005 in central Au+Au collisions, indicating an evolution from a highly non-equilibrated system in p+p collisions toward an almost thermalized system in central Au+Au collisions. The temperature and collective velocity are well described by a quadratic dependence on (q1)(q-1). Two sets of parameters in our Tsallis Blast-Wave model are required to describe the meson and baryon groups separately in p+p collisions while one set of parameters appears to fit all spectra in central Au+Au collisions.

Keywords

Cite

@article{arxiv.0812.1609,
  title  = {Spectra and radial flow at RHIC with Tsallis statistics in a Blast-Wave description},
  author = {Zebo Tang and Yichun Xu and Lijuan Ruan and Gene van Buren and Fuqiang Wang and Zhangbu Xu},
  journal= {arXiv preprint arXiv:0812.1609},
  year   = {2014}
}

Comments

6 pages, 3 figures; update text and references