Charged hadron results from Au+Au at 19.6 GeV

Abstract

Results from a one day $\sqrt{s_{NN}} = 19.6$ GeV Au+Au test run at RHIC using the STAR detector are presented. The quality of these results from only 175,000 triggered events demonstrates some of STAR's physics capabilities for the upcoming beam energy scan at RHIC. From these 19.6 GeV Au+Au collisions, we have analyzed the transverse mass spectra of $\pi^{\pm}$, $K^{\pm}$, $p$, and $\bar{p}$ at midrapidity and $m_T - m_0$ $< 1.0$ GeV/$c^2$. We have also measured the two-pion interferometry source radii. The collision energy ($\sqrt{s_{NN}} = 19.6$ GeV) of this low energy Au+Au RHIC collider run is very close to that of the 158 AGeV fixed-target Pb+Pb runs at the SPS ($\sqrt{s_{NN}} = 17.3$ GeV). We present comparisons between these STAR data and the results published by NA49, NA44, WA98, and CERES.