A Right-handed Neutrino Portal to the Hidden sector : Active Neutrinos and their Twins in an F-theory model

TL;DR

This paper explores a string theory-inspired model where right-handed neutrinos connect the visible and hidden sectors, leading to unique neutrino mass patterns and potential cosmological implications.

Contribution

It introduces a novel F-theory model with right-handed neutrinos coupling both sectors, resulting in a distinctive neutrino mass spectrum and phenomenology.

Findings

Active neutrinos are mostly massless and acquire mass radiatively.

Massive neutrinos are mainly sterile, arising from the seesaw mechanism.

The model fits observed neutrino masses and mixing angles.

Abstract

We analyze the neutrino phenomenology in an $SU(5)$ F-theory model with both a visible sector and a twin hidden sector. At low energies, the strong and weak scales of the two sectors may differ but the spectrum of states is described by the MSSM (MSSM$^\prime$) in the visible (twin) sectors. What is special about the model is that there are right-handed neutrinos which couple to both sectors via Yukawa couplings. As a result, assuming 3 right-handed neutrinos with a large mass much greater than the weak scale, at tree-level the seesaw mechanism results in 3 massive Majorana neutrinos and 3 massless ones. The massless neutrinos acquire mass via radiative corrections. In our analysis, the massless neutrinos are predominantly active neutrinos, while the massive neutrinos are predominantly sterile neutrinos. We fit the active neutrino masses and mixing angles and discuss the phenomenology of the lightest sterile neutrino. Finally we consider some possible scenarios for cosmology.