Georgi, HowardGlashow, Sheldon2016-09-071999Georgi, Howard, and Sheldon L. Glashow. 1999. “Soft Superweak CP Violation and the Strong CP Puzzle.” Physics Letters B 451 (3-4) (April): 372–381. doi:10.1016/s0370-2693(99)00246-4.0370-2693http://nrs.harvard.edu/urn-3:HUL.InstRepos:28265572We discuss a class of models in which CP is violated softly in a heavy sector adjoined to the standard model. Heavy-sector loops produce the observed CP violation in kaon physics, yielding a tiny and probably undetectable value for ǫ′. All other CPviolating parameters in the effective low-energy standard model, including the area of the unitarity triangle and θ, are finite, calculable and can be made very small. The leading contribution to θ comes from a four-loop graph. These models offer a natural realization of superweak CP violation and can resolve the strong CP puzzle. In one realization of this idea, CP is violated in the mass matrix of heavy majorana neutrinos.en-USJournal Article2016-09-0710.1016/S0370-2693(99)00246-4