Gluing Branes II: Flavour Physics and String Duality

TL;DR

This paper explores how degenerate brane configurations can be used to engineer flavour physics in string theory, addressing major problems like the mu-problem and proton decay, and investigates heterotic/F-theory duality through Fourier-Mukai transforms.

Contribution

It introduces the use of gluing in brane configurations to solve flavour physics issues and analyzes heterotic monad constructions via Fourier-Mukai transforms in duality contexts.

Findings

Gluing provides a tool to engineer flavour structures in F-theory and type IIb.

Degenerate structures can address the mu-problem, doublet/triplet splitting, and proton decay.

Fourier-Mukai transform of heterotic monads helps explore strong coupling phenomena.

Abstract

Recently we discussed new aspects of degenerate brane configurations, which can appear in the context of heterotic strings, perturbative type II, or M/F-theory. Here we continue our study of degenerate brane configurations, focussing on two applications. First we show how the notion of gluing can be viewed as a tool to engineer flavour structures in F-theory and type IIb, such as models with bulk matter and with Yukawa textures arising from the holomorphic zero mechanism. We find that there is in principle enough structure to solve some of the major flavour problems without generating exotics. In particular, we show how this addresses the mu-problem, doublet/triplet splitting and proton decay. Secondly, we describe the Fourier-Mukai transform of heterotic monad constructions, which occur in the large volume limit of heterotic linear sigma model vacua. Degenerate structures again often appear. One may use this to explore strong coupling phenomena using heterotic/F-theory duality.