Speaker: Rob Pisarski (BNL)

Title: Why the chiral phase transition for three light flavors is so interesting

Abstract: Abstract: In QCD, the eta prime meson is heavy because the breaking of the anomalous U_A(1) symmetry is large. A simple argument suggests that it should then be easy to see a first order chiral transition for light quarks.  Nevertheless, numerical simulations on the lattice see no evidence for such a first order chiral transition. I suggest that this occurs because the usual power counting for anomalous operators is more subtle than expected.  This leads to numerous predictions for different numbers of quark flavors. The case of a single flavor is especially interesting.  It also suggests novel experimental signals.

Bio: Rob Pisarski was an undergraduate at Yale, where he studied under Feza Gursey.  He received his Ph.D. from Princeton in 1979, with David Gross. After returning to Yale as the last Gibbs Fellow, and positions at Santa Barbara and Fermilab, he went to Brookhaven in 1989, where he has been since.  Besides his work on Chern-Simons theories in the '80s, he is known for his work on gauge theories at non-zero temperature and density, including Hard Thermal Loops, effective theories of deconfinement, quarkyonic matter, and most recently, moat spectra.