Speaker
Description
The exploration of QCD phase diagram and study of the dynamics and mechanism of particle production in heavy-ion collisions is one of the research interests in the field of high energy physics. In addition, the search for the QCD critical point in the phase diagram has been the main motivation to carry out the Beam Energy Scan Phase - I (BES-I) program at the Relativistic Heavy Ion Collider (RHIC) facility at BNL. Under this program in the years 2010 and 2011, Au+Au collisions were recorded at $\sqrt{s_{NN}} =$ 7.7, 11.5, 19.6, 27 and 39 GeV by the STAR detector at RHIC. Later in the year 2014, Au+Au collisions at $\sqrt{s_{NN}} = 14.5$ GeV were added to this BES program.
We will present results of the identified particle production from the BES energies. Our study focuses on the extraction of the chemical and kinetic freeze-out properties of the system and understanding the evolution and dynamics of particle production. This study is also interesting since at the top RHIC energies it was found that the hadron-QGP phase transition occurs close to the chemical freeze-out temperature. With this in mind, we will present the measured transverse momentum ($p_{T}$) spectra, particle yields ($dN/dy$) and average transverse momentum ($\langle p_{T} \rangle$) of $\pi^{\pm}$, $K^{\pm}$, $p(\bar{p})$. Using these observables, the calculated freeze-out parameters, most importantly the chemical freeze-out temperature ($T_{ch}$), baryon chemical potential ($\mu_{B}$), kinetic freeze-out temperature ($T_{k}$) and radial flow velocity ($\beta$) will be presented. The variation of all these observables with the collision centrality and center of mass energy will be discussed with the published data from STAR. A comparison of these results with the published results of STAR in Au+Au collision at $\sqrt{s_{NN}} =$ 62.4 and 200 GeV and ALICE in Pb+Pb collision at $\sqrt{s_{NN}} = 2.76$ TeV will also be shown.
