On 'Light' Fermions and Proton Stability in 'Big Divisor' D3/D7 Swiss Cheese Phenomenology

TL;DR

This paper explores how light fermion masses and proton stability can be achieved in type IIB string theory compactifications on Swiss-Cheese orientifolds with D3/D7-branes, providing new insights into particle physics phenomenology.

Contribution

It demonstrates the generation of light fermion mass scales and shows the absence of proton decay operators in a specific string theory setup, with estimates of proton lifetime.

Findings

Light fermion masses in MeV-GeV and eV ranges are achievable.

Proton decay operators are absent, ensuring proton stability.

Estimated proton lifetime exceeds 10^{61} years.

Abstract

Building up on our earlier work [1,2], we show the possibility of generating "light" fermion mass scales of MeV-GeV range (possibly related to first two generations of quarks/leptons) as well as eV (possibly related to first two generations of neutrinos) in type IIB string theory compactified on Swiss-Cheese orientifolds in the presence of a mobile space-time filling D3-$brane restricted to (in principle) stacks of fluxed D7-branes wrapping the "big" divisor \Sigma_B. This part of the paper is an expanded version of the latter half of section 3 of a published short invited review [3] written up by one of the authors [AM]. Further, we also show that there are no SUSY GUT-type dimension-five operators corresponding to proton decay, as well as estimate the proton lifetime from a SUSY GUT-type four-fermion dimension-six operator to be 10^{61} years. Based on GLSM calculations in [1] for obtaining the geometric Kaehler potential for the "big divisor", using further the Donaldson's algorithm, we also briefly discuss in the first of the two appendices, obtaining a metric for the Swiss-Cheese Calabi-Yau used, that becomes Ricci flat in the large volume limit.