Soft superweak CP violation and the strong CP puzzle

We discuss a class of models in which CP is violated softly in a heavy sect or adjoined to the standard model. Heavy-sector loops produce the observed CP violation in kaon physics, yielding a tiny and probably undetectable val ue for epsilon'. All other CP-violating parameters in the effective low-ene rgy standard model, including the area of the unitarity triangle and <(thet a)over bar>, are finite, calculable and can be made very small. The leading contribution to <(theta)over bar> comes from a four-loop graph. These mode ls offer a natural realization of superweak CP violation and can resolve th e strong CP puzzle. In one realization of this idea, CP is violated in the mass matrix of heavy majorana neutrinos. (C) 1999 Published by Elsevier Sci ence B.V. All rights reserved.