Speaker
Description
Femtoscopic measurements can be leveraged to gain insight into the expansion dynamics of the hot and dense medium created in heavy-ion collisions. This poster presentation will report and discuss excitation functions for shape-selected two-pion HBT radii ($R_{out}$, $R_{side}$ and $R_{long}$) measured for a a broad range of collision centrality and average pair transverse momentum ($k_{T}$) with the STAR detector. The shape selections were accomplished via cuts on the distributions of the second-order $Q_2$ vector [1]. The excitation functions, which span the full range of the RHIC beam energy scan ($\sqrt{s_{NN}}$ = 7.7-200 GeV), indicate clear sensitivities to the magnitude of the $Q_2$ vector which give insight into the expansion dynamics. The connection between the magnitude of the $Q_2$ vector and the spatiotemporal characteristics of the quark-gluon plasma produced in the collisions will be discussed.
[1] J. Schukraft, A. Timmins, and S. A. Voloshin, Phys. Lett. B 719 (2013) 394.
