Abstract

We present measurements of bulk properties of the matter produced in Au+Au collisions at root sNN = 7.7, 11.5, 19.6, 27, and 39 GeV using identified hadrons (pi, K, p and (p) over bar) from the STAR experiment in the Beam Energy Scan (BES) Program at the Relativistic Heavy Ion Collider (RHIC). Midrapidity (|y| 0.1) results for multiplicity densities dN/dy, average transverse momenta p(T)> and particle ratios are presented. The chemical and kinetic freeze-out dynamics at these energies are discussed and presented as a function of collision centrality and energy. These results constitute the systematic measurements of bulk properties of matter formed in heavy-ion collisions over a broad range of energy (or baryon chemical potential) at RHIC.