CP, T and fundamental interactions
  We discuss the importance of the CP (simultaneous particle-antiparticle and left-right permutation) and T (time reversal) symmetries in the context of fundamental interactions. We show that they may provide clues to go beyond the 4-D gauge interactions. We insist on the fact that T violation is not associated to a degradation (like in entropy), but simply characterized by different trajectories. 
J-M. Fr\`ere
hep-ph hep-th