  Femtoscopic measurements at RHIC have been hailed as a source of insight into
the bulk properties of QCD matter. However, hydrodynamic models, which have
been successful in reproducing other observables have failed to satisfactorily
explain femtoscopic two-particle correlation measurements. This failure has
been labeled the "HBT puzzle". In this talk, I present correlations using a
hybrid model composed of a viscous hydrodynamic module and a hadronic cascade.
After incorporating early acceleration, viscosity and a stiffer equation of
state, the extracted source sizes come much closer to experiment.

Nuclear Theory