PNJL model analysis of the Roberge-Weiss transition endpoint at   imaginary chemical potential
  Motivated by lattice QCD studies we investigate the RW transition endpoint at imaginary chemical potential in a two-flavor PNJL model. We focus on the quark-mass dependence of the endpoint using different forms of the Polyakov-loop potential. 
David Scheffler, Michael Buballa, Jochen Wambach
hep-ph