Gauge Mediated Supersymmetry Breaking and Spontaneous CP Violation as a Solution to the Strong CP Problem

Abstract

The origin of CP violation is a major mystery, especially in relation to the strong CP problem. CP being a spontaneously broken symmetry could provide an elegant solution. However, such models have difficulty making themselves compatible with low-energy supersymmetry, which is popularly accepted as the solution to the hierarchy problem. We demonstrate that a certain class of low scale supersymmetric ``Nelson-Barr'' type models can solve the strong and supersymmetric CP problems while at the same time generating sufficient weak CP violation in the $K^0-{\bar{K}}^0$ system. Gauge-mediated supersymmetry breaking is used to provide the needed squark mass degeneracies and $A$-term proportionalities; though that proves to be still insufficient for a generic Nelson-Barr model. The workable model we consider here, essentially a supersymmetric version of the aspon model, has the Nelson-Barr mass texture enforced by a U(1) gauge symmetry, broken at the TeV scale. The resulting model is predictive with rich phenomenology soon to be available. Feasibility of the model considered is established by a detailed renormalization group studies.

Comments: 3 pages + cover, in LATEX with sprocl.sty, talks given by PASCOS 98 and 4th International Workshop on Particle Phenomenology (Taiwan)