Lepton number and flavour violation in TeV-scale left-right symmetric theories with large left-right mixing

Abstract

The various diagrams leading to neutrinoless double beta decay in the left-right symmetric model have different relative magnitudes, depending on the scale of new physics. Neutrinos acquire mass from both type I and/or type II seesaw terms, making an unambiguous analysis difficult. We study the half-life for double beta decay in the case of type II and type I dominance, in the former case including interference terms. If the heavy neutrinos of the type I seesaw model are at the TeV scale, certain processes can be enhanced. In particular, there are regions of parameter space in which the so-called λ-and η-diagrams can give sizable contributions to the half-life for the decay. We perform a detailed study of one such scenario, paying careful attention to constraints from lepton flavour violation. *

Charged lepton flavour violcxmation and neutrinoless double beta decay in left-right symmetric models with type I+II seesaw

“…More recently, the authors of [32,52,53] studied the new physics contributions to 0νββ process for TeV scale MLRSM with dominant type II seesaw. There have also been several works [54][55][56][57] where type I seesaw limit was also included into the computation of 0νββ in MLRSM. Some more detailed analyses incorporating left-right gauge mixing were discussed in the works [58][59][60][61][62].…”

Proton decay and new contribution to 0ν2β decay in SO(10) with low-mass Z′ boson, observable n − n ¯ $$ n-\overline{n} $$ oscillation, lepton flavor violation, and rare kaon decay

“…JHEP01 (2015) Using results discussed in previous sections, the inverse half-life is presented in terms of η− parameters and others including the nuclear matrix elements [39,[82][83][84] T 0ν…”

“…Explicit numerical values of these nuclear matrix elements discussed in refs. [39,[82][83][84] are given in table 4.…”

TeV scale universal seesaw, vacuum stability and heavy Higgs

“…Since the neutrinos in this case are Majorana fermions, they would give rise to neutrino-less double beta decay. In this case the collider phenomenology is similar to the conventional TeV scale left-right seesaw case [64][65][66][67][68][69][70][71][72][73][74]. Our goal in this paper is simply to demonstrate that getting small neutrino masses does not pose any challenge to the viability of these models.…”