Seesaw scale, unification, and proton decay

Pavel Fileviez Pérez,Axel Gross,Clara Murgui

doi:10.1103/physrevd.98.035032

Pavel Fileviez Pérez, Axel Gross + Show 1 more

Open Access

https://doi.org/10.1103/physrevd.98.035032

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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.

Highlights

One of the main goals of theoretical physics is to understand the unification of fundamental forces in nature.In 1974, H
We investigate a simple realistic grand unified theory based on the SUð5Þ gauge symmetry, which predicts an upper bound on the proton decay lifetime for the channels p → Kþνand p → πþν, i.e., τðp → KþνÞ ≲ 3.4 × 1035 and τðp → πþνÞ ≲ 1.7 × 1034 years, respectively
The neutrino masses are generated through the type I and type III seesaw mechanisms, but in this case, the new vectorlike fermions play a crucial role

Summary

INTRODUCTION

One of the main goals of theoretical physics is to understand the unification of fundamental forces in nature. We investigate a simple renormalizable extension of the Georgi-Glashow model that corrects the three major problems with the Georgi-Glashow model: neutrino masses, consistent charged fermion masses, and unification of gauge couplings In this theory, one can achieve a consistent relation between the charged fermion masses by adding vectorlike fermions in the 50 and 5 ̄0 representations. The neutrino masses are generated through the type I and type III seesaw mechanisms, but in this case, the new vectorlike fermions play a crucial role In this context, we show that we can achieve the unification of the gauge couplings in agreement with the low energy constraints. This article is organized as follows: In Sec. II, we discuss the main features of our model: the unification constraints, the generation of neutrino and charged fermion masses, and the predictions for proton decay.

THEORETICAL FRAMEWORK

Gauge unification constraints

Proton decay

Neutrino masses

Charged fermion masses

SUMMARY