Towards thermalization in heavy-ion collisions: CGC meets the 2PI   formalism
  We propose to apply the two-particle irreducible (2PI) formalism to the problem of thermalization in heavy-ion collisions in the Color Glass Condensate (CGC) picture. We consider the 2PI effective action to three loops and derive a set of coupled equations for the classical Yang-Mills field and the quantum fluctuations in the boost invariant coordinate system. The initial condition and the relation to previous works are also discussed. 
Yoshitaka Hatta and Akihiro Nishiyama
hep-ph