Van Hove Singularities in the Quark-Gluon Plasma
  General arguments as well as different approximations for the in-medium quark propagator in a quark-gluon plasma lead to quark dispersion relations that exhibit a minimum in one branch (plasmino). This minimum causes Van Hove singularities in the dilepton production rate and mesonic correlators, which might have observable consequences. 
Markus H. Thoma