Yukawa Textures in Heterotic M-Theory

TL;DR

This paper explores how Yukawa couplings and quark hierarchies can be naturally explained within heterotic M-theory, specifically through non-standard embeddings and specific geometric configurations, avoiding fine tuning.

Contribution

It demonstrates a phenomenological model in heterotic M-theory that accounts for quark masses and CKM matrix without fine tuning, using 5-brane clustering and specific instanton charge conditions.

Findings

CKM and quark mass hierarchies explained without fine tuning

A specific Calabi-Yau manifold configuration satisfies all data

5-branes cluster near the second orbifold plane

Abstract

We examine the structure of the Yukawa couplings in the 11 dimensional Horava-Witten M-theory based on non-standard embeddings. We find that the CKM and quark mass hierarchies can be explained in M Theory without introducing undue fine tuning. A phenomenological example is presented satisfying all CKM and quark mass data requiring the 5-branes cluster near the second orbifold plane, and that the instanton charges of the physical orbifold plane vanish. The latter condition is explicitly realized on a Calabi-Yau manifold with del Pezzo base dP_7.