Model of Soft CP Violation

Abstract

We propose a model of soft CP violation that evades the strong CP problem and can describe observed CP violation in the neutral kaon sector, both direct and indirect. Our model requires two ``duark'' mesons carrying quark number two that have complex (CP-violating) bare masses and are coupled to quark pairs. Aside from the existence of these potentially observable new particles with masses of several hundred GeV, we predict a flat unitarity triangle ({\it i.e.,} no observable direct CP violation in the $B$-meson sector) and a possibly anomalous branching ratio for the decay mode $K^+\to \pi^++\bar{\nu} \nu$.