Speaker
Description
One of the main physics goals of the Beam Energy Scan (BES) program at RHIC is to study the QCD phase diagram, especially around the phase transition between the quark-gluon plasma (QGP) and hadronic matter. BES Phase-I studied Au+Au collisions from center-of-mass energy ($\sqrt{s_{_{\rm{NN}}}} $) of 7.7 to 62.4 GeV. BES Phase-II extended these measurements in several important ways, one of which was the addition of a fixed-target program that pushed the collision energy down to 3.0 GeV (or baryon chemical potential, $\mu_{\rm{B}}$, up to 720 MeV). Fixed-target collisions at STAR allow for a more extensive scanning of the QCD phase diagram to an important region where the QCD critical point may lie, and to a region dominated by dense baryonic matter. One key measurement in the fixed-target program is the spectrum of the lightest hadrons [$\pi^{\pm}, \ \rm{K^{\pm}}$, p($\rm \bar{ p}$)] as a function of transverse momentum, rapidity, and collision centrality. Such measurements enable the empirical determination of the colliding system's location on the phase diagram at chemical freeze-out. This talk details the latest status of the light hadron production measurements at STAR, and $dN/dy$ measurements are shown from $\sqrt{s_{_{\rm{NN}}}} = 3.2 - 4.5$ GeV.
