PHENIX measurements of 3D emission source functions in Au+Au collisions at s_NN = 200 GeV GeV

A state-of-the-art 3D source imaging technique is used to extract the 3D two-pion source function in central and mid-central Au+Au collisions at s _NN = 200 GeV. The source function indicates a previously unresolved non-Gaussian tail in the directions of the pion pair transverse momentum (out) and along the beam (long). Model comparisons give robust estimates for several characteristics of the emission source, including its transverse size, mean proper breakup time τ and emission duration Δτ. These estimates point to significant relative emission times which could result from a crossover phase transition.