Flavor Violation in a Minimal SO(10)\times A_4 SUSY GUT

TL;DR

This paper investigates flavor violation in a minimal supersymmetric SO(10) x A4 grand unified theory, showing how exotic heavy fermions induce flavor violation at the GUT scale and analyzing constraints from lepton flavor-violating decays.

Contribution

It introduces a realistic SO(10) x A4 SUSY GUT model with exotic heavy fermions that explains fermion masses and mixings, and studies flavor violation constraints.

Findings

Flavor violation is induced at the GUT scale due to exotic fermion mixings.

Degenerate slepton masses around 1 TeV satisfy experimental constraints.

The model suppresses flavor-changing neutral currents effectively.

Abstract

Flavor violating processes in the quark and lepton sectors are investigated within a realistic supersymmetric $SO(10)\times A_4$ grand unification model. By employing exotic heavy fermion fields, this model successfully describes various features of the fermion masses and mixings including large neutrino mixings accompanied by small quark mixings. In this model the flavor violation is induced at GUT scale, at which $A_4$ flavor symmetry is broken, as a consequence of the large mixings of the light fermion fields with these exotic heavy fields. The stringent experimental constraint from $\mu\rightarrow e\gamma$ decay rate necessitates a high degree of degeneracy of the supersymmetry breaking soft scalar masses of the exotic heavy fields and supersymmetric scalar partners of the light fermion fields. The choice of slepton masses of order 1 TeV is found to be consistent with the constraints from branching ratio of $\mu\rightarrow e\gamma$ and with all other flavor changing neutral current processes being sufficiently suppressed.