Seesaw Scale, Unification, and Proton Decay

TL;DR

This paper presents a realistic SU(5) grand unified theory predicting specific upper bounds on proton decay lifetimes and links neutrino mass generation to testable seesaw mechanisms, with implications for current and future experiments.

Contribution

It introduces a simple SU(5) GUT model with testable proton decay predictions and a light field for type III seesaw below 500 TeV.

Findings

Proton decay lifetime bounds: rac{p o K^+ ar{ u}}{ au} \u2264 3.4 imes 10^{35} years

Type III seesaw field predicted below 500 TeV

Model testability at current and future proton decay experiments

Abstract

We investigate a simple realistic grand unified theory based on the $SU(5)$ gauge symmetry which predicts an upper bound on the proton decay lifetime for the channels $p \to K^+ \bar{\nu}$ and $p \to \pi^+ \bar{\nu}$, i.e. $\tau (p \to K^+ \bar{\nu}) \lesssim 3.4 \times 10^{35}$ and $\tau (p \to \pi^+ \bar{\nu}) \lesssim 1.7 \times 10^{34}$ years, respectively. In this context, the neutrino masses are generated through the type I and type III seesaw mechanisms, and one predicts that the field responsible for type III seesaw must be light with a mass below 500 TeV. We discuss the testability of this theory at current and future proton decay experiments.