Pion interferometry with L\'evy-stable sources in $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions at STAR

Abstract

Measurements of femtoscopic correlations in high-energy heavy-ion collisions aim to unravel the space-time structure of the particle-emitting source (the quark-gluon plasma). Recent results indicate that the pion pair source exhibits a power-law behavior and can be described well by a L\'evy distribution. In this study, L\'evy fits were performed to the measured one-dimensional two-pion correlation functions in Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV. The three extracted source parameters are the L\'evy scale parameter, $R$, which relates to the size of the source; the correlation strength parameter, $\lambda$; and the L\'evy exponent, $\alpha$, which characterizes the power-law tail of the source. In this paper, we report the current status of the analysis of the extracted L\'evy source parameters and present their dependence on average transverse mass, $m_T$, and on centrality.