The RHIC HBT puzzle, chiral symmetry restoration, and pion opacity Original Research Article

We present a relativistic quantum wave-mechanical optical model treatment of the opacity and refractive effects of pions emerging from a hot dense expanding source. The Klein-Gordon equation with Bjorken-cylinder geometry is solved for distorted waves representing the emerging pions. These waves are combined with a hydro-inspired pion source function to predict HBT radii and pion spectra. The model, when using a very deep potential well, has produced excellent HBT radii and spectrum fits to RHIC View the MathML source Au+Au data from STAR, reproducing the observed small source sizes, RO/RS≈1, the low-momentum behavior of the radii, and the pion spectrum in shape and magnitude. The calculations represent a new tool for investigating the presence and characteristics of chiral symmetry restoration in heavy ion collisions.