Hadron Production and Freeze-Out Dynamics in $\sqrt{s_{NN}}$ Au+Au at RHIC

The Beam Energy Scan (BES) program at RHIC was commissioned to search for the critical point and the turn-on of QGP signatures. STAR has collected data from collisions of $Au+Au$ at energies from 7.7 to 62.4 GeV per nucleon pair. The addition of a full-coverage Time-of-Flight detector at STAR has extended the momentum range for clean particle identification. The freeze-out parameters can be extracted from the measured hadron spectra. In this talk, we will present STAR preliminary results of particle spectra from $\sqrt{s_{NN}}$ = 19.6 GeV $Au+Au$ collisions. Distributions of $\pi, K, p$ and $\bar{p}$ as a function of $m_{T}-m_{0}$ will be used to discuss the chemical and kinetic freeze-out properties. In addition, we will compare these results with earlier BES data from STAR.