English

Kinetic freeze-out temperature from yields of short-lived resonances

High Energy Physics - Phenomenology 2020-08-14 v3 Nuclear Experiment Nuclear Theory

Abstract

A method to determine the kinetic freeze-out temperature in heavy-ion collisions from measured yields of short-lived resonances is presented. The resonance production is treated in the framework of thermal model with an evolution between chemical and kinetic freeze-outs. The yields of many short-lived resonances are suppressed at T=Tkin<TchT = T_{\rm kin} < T_{\rm ch}. We determine the values of TkinT_{\rm kin} and TchT_{\rm ch} for various centralities in Pb--Pb collisions at sNN=2.76\sqrt{s_{_{NN}}} = 2.76 TeV by fitting the abundances of both the stable hadrons and the short-lived resonances such as ρ0\rho^0 and K0 \text{K}^{*0}, that were measured by the ALICE collaboration. This allows to extract the kinetic freeze-out temperature from the measured hadron and resonance yields alone, independent of assumptions about the flow velocity profile and the freeze-out hypersurface. The extracted TchT_{\rm ch} values exhibit a moderate multiplicity dependence whereas TkinT_{\rm kin} drops, from TkinTch155T_{\rm kin} \simeq T_{\rm ch} \simeq 155 MeV in peripheral collisions to Tkin110T_{\rm kin} \simeq 110 MeV in 0-20% central collisions. Predictions for other short-lived resonances are presented. A potential (non-)observation of a suppressed f0(980)f_0(980) meson yield will allow to constrain the lifetime of that meson.

Keywords

Cite

@article{arxiv.1908.11730,
  title  = {Kinetic freeze-out temperature from yields of short-lived resonances},
  author = {Anton Motornenko and Volodymyr Vovchenko and Carsten Greiner and Horst Stoecker},
  journal= {arXiv preprint arXiv:1908.11730},
  year   = {2020}
}

Comments

6 pages, 3 figures. Version published in Physical Review C