Evaluations of freeze-out parameters from $\frac{d{E}_T}{d\eta }/\frac{d{N}_{ch}}{d\eta }$ ratio measured at RHIC and SPS

Abstract

In the presented paper curves of constant ${ϵ}_T/n_{charged}$ are calculated in $T-{\mu }_B$ plane, in the framework of a single-freeze-out thermal hadron gas model. The ratio is a theoretical equivalent of ${\frac{d{E}_T}{d\eta }}_{\mid \eta =0}/{\frac{d{N}_{ch}}{d\eta }}_{\mid \eta =0}$ measured at RHIC and SPS. In both ${ϵ}_T$ and $n_{charged}$ decays of hadron resonances are taken into account. The freeze-out temperature $T_{f.o.}=156_{-11}^{+14}$ MeV is obtained for RHIC, whereas $T_{f.o.}=134-140$ MeV is evaluated for SPS.

Comments: Revtex, 3 figures (included), 5 pages, conclusions concerning AGS have been withdrawn