Pion Interferometry at RHIC: Probing a Thermalized Quark-Gluon Plasma?

We calculate the Gaussian radius parameters of the pion-emitting source in high-energy heavy-ion collisions, assuming a first-order phase transition from a thermalized quark-gluon plasma (QGP) to a gas of hadrons. Such a model leads to a very long-lived dissipative hadronic rescattering phase which dominates the properties of the two-pion correlation functions. The radii are found to depend only weakly on the thermalization time ${\tau }_i$, the critical temperature $T_c$ (and thus the latent heat), and the specific entropy of the QGP. The model calculations suggest a rapid increase of $R_{\mathrm{out}}/R_{\mathrm{side}}$ as a function of $K_T$ if a thermalized QGP were formed.