Charting the flavor landscape of MSSM-like Abelian heterotic orbifolds

TL;DR

This paper classifies flavor symmetries in 4D spectra from heterotic orbifold compactifications, revealing prevalent D4 factors and rare Delta(54) symmetries, aiding understanding of flavor origins in string theory.

Contribution

It provides the widest known classification of flavor symmetries in E8 x E8 heterotic orbifolds, including non-factorizable spaces and roto-translations.

Findings

75.4% of models have D4 flavor symmetry factors

Only 1.2% of models exhibit Delta(54) symmetry

Majority of models have purely Abelian flavor symmetries

Abstract

Discovering a selection principle and the origin of flavor symmetries from an ultraviolet completion of particle physics is an interesting open task. As a step in this direction, we classify all possible flavor symmetries of 4D massless spectra emerging from supersymmetric Abelian orbifold compactifications, including roto-translations and non-factorizable compact spaces, for generic moduli values. Although these symmetries are valid in all string theories, we focus on the E8 x E8 heterotic string. We perform the widest known search of E8 x E8 Abelian orbifold compactifications, yielding over 121,000 models with MSSM-like features. About 75.4% of these models exhibit flavor symmetries containing D4 factors and only nearly 1.2% have Delta(54) factors. The remaining models are furnished with purely Abelian flavor symmetries. Our findings suggest that, should particle phenomenology arise from a heterotic orbifold, it could accommodate only one of these flavor symmetries.