Transverse Momentum and Rapidity Dependence of HBT Correlations in Au+Au Collisions at sqrt(s_NN) = 62.4 and 200 GeV

Abstract

Two-particle correlations of identical charged pion pairs from Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV were measured by the PHOBOS experiment at RHIC. Data for the 15% most central events were analyzed with Bertsch-Pratt and Yano-Koonin-Podgoretskii parameterizations using pairs with rapidities of 0.4 < y_{\pi\pi} < 1.3 and transverse momenta 0.1 < k_T < 1.4 GeV/c. The Bertsch-Pratt radii R_o and R_l decrease as a function of pair transverse momentum, while R_s is consistent with a weaker dependence. R_o and R_s are independent of collision energy, while R_l shows a slight increase. The source rapidity y_{ykp} scales roughly with the pair rapidity y_{\pi\pi}, indicating strong dynamical correlations.Comment: 5 pages, 4 figures, 2 tables, submitted to Phys. Rev.