On the neutrality issue in the Polyakov-loop NJL model
  We elucidate how the color neutrality is harmed in the Polyakov Nambu-Jona Lasinio (PNJL) model at finite density within the adopted mean field approximation. Also we point out how usual assumption about the diagonal form of the Wilson loop may fail in the presence of the diquark condensate on several grounds. 
H. Abuki, M. Ciminale, R. Gatto and M. Ruggieri