Towards a Realistic Picture of CP Violation in Heterotic String Models

TL;DR

This paper explores how heterotic string models can naturally produce CP violation through complex moduli VEVs, while avoiding problematic CP phases in soft SUSY-breaking terms, offering a more realistic picture of CP violation.

Contribution

It demonstrates that dilaton dominated SUSY breaking and spontaneous CP violation can occur in heterotic models with specific superpotentials, providing a semi-realistic CP violation scenario.

Findings

CKM phase arises from complex T-modulus VEV

Soft SUSY CP phases are suppressed by an axionic symmetry

Models achieve spontaneous CP violation without conflicting with experimental constraints

Abstract

We find that dilaton dominated supersymmetry breaking and spontaneous CP violation can be achieved in heterotic string models with superpotentials singular at the fixed points of the modular group. A semi--realistic picture of CP violation emerges in such models: the CKM phase appears due to a complex VEV of the T-modulus, while the soft supersymmetric CP phases are absent due to an axionic--type symmetry.