SEMINAR      Monday, 23 January 2006 - h. 15:00  Aula B1    Michael Creutz (Brookhaven National Laboratory) Spontaneous CP violation in the strong interactions and quark mass ambiguities Abstract I explore the regions of quark masses where CP will be spontaneously broken in the strong interactions. The boundaries of these regions are controlled by the chiral anomaly, which manifests itself in ambiguities in the definition of non-degenerate quark masses. In particular, the concept of a single massless quark is ill defined.