# Neutrinoless Double Beta Decay in Left-Right Symmetry with Universal Seesaw

## TL;DR

This paper explores a left-right symmetric model with a universal seesaw mechanism, where neutrino masses are dominated by type-II seesaw, and examines its implications for neutrinoless double beta decay and gauge unification.

## Contribution

It introduces a novel left-right symmetric framework with universal seesaw and type-II dominance, absent of Dirac neutrino masses, impacting $0
uetaeta$ decay predictions.

## Key findings

- Type-II seesaw dominance achieved naturally without Dirac masses.
- Heavy neutrinos can have masses of a few TeV.
- Model implications for neutrinoless double beta decay and gauge unification.

## Abstract

We discuss a class of left-right symmetric theories with a universal seesaw mechanism for fermion masses and mixing and the implications for neutrinoless double beta ($0\nu\beta\beta$) decay where neutrino masses are governed by natural type-II seesaw dominance. The scalar sector consists of left- and right-handed Higgs doublets and triplets, while the conventional Higgs bidoublet is absent in this scenario. We use the Higgs doublets to implement the left-right and the electroweak symmetry breaking. On the other hand, the Higgs triplets with induced vacuum expectation values can give Majorana masses to light and heavy neutrinos and mediate $0\nu\beta\beta$ decay. In the absence of the Dirac mass terms for the neutrinos, this framework can naturally realize type-II seesaw dominance even if the right-handed neutrinos have masses of a few TeV. We study the implications of this framework in the context of $0\nu\beta\beta$ decay and gauge coupling unification.