Observable Proton Decay in Flipped SU(5)

TL;DR

This paper investigates proton decay predictions in supersymmetric flipped SU(5) models with a U(1)_R symmetry, identifying testable proton lifetime regions and analyzing gauge unification with intermediate scales.

Contribution

It introduces realistic flipped SU(5) models with U(1)_R symmetry, exploring proton decay channels, intermediate scale particles, and gauge unification, providing testable predictions for future experiments.

Findings

Proton decay channels include p→e+π0, p→μ+K0, and others.

Certain parameter regions predict proton lifetimes within Hyper-Kamiokande sensitivity.

Intermediate scale particles are crucial for gauge coupling unification.

Abstract

We explore proton decay in a class of realistic supersymmetric flipped $SU(5)$ models supplemented by a $U(1)_R$ symmetry which plays an essential role in implementing hybrid inflation. Two distinct neutrino mass models, based on inverse seesaw and type I seesaw, are identified, with the latter arising from the breaking of $U(1)_R$ by nonrenormalizable superpotential terms. Depending on the neutrino mass model an appropriate set of intermediate scale color triplets from the Higgs superfields play a key role in proton decay channels that include $p \rightarrow (e^{+},\mu^+)\, \pi^0$, $p \rightarrow ( e^+,\mu^{+})\, K^0 $, $p \rightarrow \overline{\nu}\, \pi^{+}$, and $p \rightarrow \overline{\nu}\, K^+ $. We identify regions of the parameter space that yield proton lifetime estimates which are testable at Hyper-Kamiokande and other next generation experiments. We discuss how gauge coupling unification in the presence of intermediate scale particles is realized, and a $Z_4$ symmetry is utilized to show how such intermediate scales can arise in flipped $SU(5)$. Finally, we compare our predictions for proton decay with previous work based on $SU(5)$ and flipped $SU(5)$.