Solving the SUSY Flavour and CP Problems with SU(3) Family Symmetry

TL;DR

This paper demonstrates how gauged SU(3) family symmetry can address SUSY flavour and CP problems, leading to suppressed electric dipole moments and specific flavor-changing predictions consistent with experimental constraints.

Contribution

It introduces a novel application of gauged SU(3) family symmetry to solve SUSY flavour and CP issues, with detailed calculations of mass matrices and CP violation effects.

Findings

Soft mass matrices satisfy flavor-changing neutral current constraints.

Predicted electric dipole moments are significantly suppressed.

Epsilon_K'/epsilon_K may be dominated by SUSY operator O_8.

Abstract

We show how the SUSY flavour and CP problems can be solved using gauged SU(3) family symmetry previously introduced to describe quark and lepton masses and mixings, in particular neutrino tri-bimaximal mixing via constrained sequential dominance. The Yukawa and soft trilinear and scalar mass squared matrices and kinetic terms are expanded in powers of the flavons used to spontaneously break the SU(3) family symmetry, and the canonically normalized versions of these matrices are constructed. The soft mass matrices are then expressed in the Super-CKM basis, and the leading order mass insertion parameters are calculated, and are shown to satisfy the experimental constraints from flavour changing neutral current processes. Assuming that CP is spontaneously broken by the flavons, the next-to-leading order effects responsible for CP violation are then estimated, and the predictions for electric dipole moments are shown to be an order of magnitude more suppressed than those predicted from the constrained minimal supersymmetric standard model (CMSSM), and may be further suppressed if the high energy trilinear soft parameter is assumed to be relatively small. We also predict that, unlike in the CMSSM, epsilon_K'/epsilon_K may be dominated by the SUSY operator O_8. We also discuss the additional constraints from unification, which can lead to further predictions for flavour changing in our scheme.