# Proton decay in flux compactifications

## TL;DR

This paper investigates proton decay in a six-dimensional orbifold GUT model with flux-induced generation multiplicity and supersymmetry breaking, predicting proton lifetimes near current experimental bounds and similar decay channel branching ratios.

## Contribution

It introduces a flux compactification model that links generation multiplicity, supersymmetry breaking, and proton decay predictions, highlighting flavor effects on decay channels.

## Key findings

- Proton lifetime is close to current experimental lower bounds.
- Decay channels $p
ightarrow e^+\pi^0$ and $p
ightarrow \mu^+\pi^0$ have similar branching ratios.
- Flavor non-diagonal couplings significantly influence decay patterns.

## Abstract

We study proton decay in a six-dimensional orbifold GUT model with gauge group $SO(10)\times U(1)_A$. Magnetic $U(1)_A$ flux in the compact dimensions determines the multiplicity of quark-lepton generations, and it also breaks supersymmetry by giving universal GUT scale masses to scalar quarks and leptons. The model can successfully account for quark and lepton masses and mixings. Our analysis of proton decay leads to the conclusion that the proton lifetime must be close to the current experimental lower bound. Moreover, we find that the branching ratios for the decay channels $p \rightarrow e^+\pi^0$ and $p\rightarrow \mu^+\pi^0$ are of similar size, in fact the latter one can even be dominant. This is due to flavour non-diagonal couplings of heavy vector bosons together with large off-diagonal Higgs couplings, which appears to be a generic feature of flux compactifications.