Seesaw-constrained MSSM, Solution to the SUSY CP Problem and a Supersymmetric Explanation of $\epsilon'/\epsilon$

TL;DR

This paper presents a seesaw-constrained MSSM model that naturally solves the SUSY CP problem and predicts an explanation for the observed $ ext{ extbackslash epsilon'} ext{/} ext{ extbackslash epsilon}$, with suppressed electric dipole moments and specific superparticle spectrum.

Contribution

It introduces a minimal left-right symmetric MSSM with a single CP-violating phase, providing a natural solution to the SUSY CP problem and explaining $ ext{ extbackslash epsilon'} ext{/} ext{ extbackslash epsilon}$ observations.

Findings

CP violation is governed by a single phase in the SUSY breaking Lagrangian.

The model predicts a neutron electric dipole moment around $4 imes 10^{-29}$ ecm.

Superparticle spectrum is tightly constrained with negligible CP asymmetries in B mesons.

Abstract

We analyze CP violation in the supersymmetric standard model (MSSM) embedded minimally into a left-right symmetric gauge structure with the seesaw mechanism for neutrino masses. With the plausible assumption of universal scalar masses it is shown that CP violation in the hadron sector of the MSSM is described by a single phase residing in the supersymmetry breaking Lagrangian. This improves the CP properties of the MSSM by providing a natural solution to the SUSY CP problem. Furthermore, $\epsilon'/\epsilon$ vanishes in this model above the seesaw scale; extrapolation to the weak scale then leads to a prediction in agreement with the NA31 and the recent KTeV observations. The electric dipole moment of the neutron is naturally suppressed, we estimate its magnitude to be about $4 \times 10^{-29}$ ecm. Additional predictions include a tightly constrained super particle spectrum and vanishingly small CP asymmetries in the $B$ meson system.