Testing Radiative Neutrino Mass Generation at the LHC

TL;DR

This paper explores a model with extended Higgs sectors that enables two-loop radiative Majorana neutrino mass generation, predicts observable doubly charged Higgs bosons at the LHC, and links these to neutrinoless double beta decay signals.

Contribution

It provides a detailed phenomenological analysis of an extended Higgs model that generates neutrino masses radiatively and predicts testable signatures at the LHC.

Findings

Doubly charged Higgs can be observed at the LHC within a large parameter space.

The model supports only a normal neutrino mass hierarchy.

Neutrinoless double beta decay is mainly mediated by doubly charged Higgs exchange.

Abstract

We have investigated in detail a model that contains an additional SU(2) singlet and triplet scalar fields than the Standard Model (SM). This allows the radiative generation of Majorana neutrino masses at two-loop order with the help of doubly charged Higgs bosons that arise from the extended Higgs sector. We studied in detail the phenomenology of the Higgs and neutrino sectors of the model. We give the analytical form of the masses of scalar and pseudoscalar bosons and their mixings, and the structure of the active neutrino mass matrix. It is found that the model accommodates only normal neutrino mass hierarchy, and that there is a large parameter space where the doubly charged Higgs can be observed at the LHC, thereby making it testable at the LHC. Furthermore, the neutrino-less double beta ($\nonu$) decays arise predominantly from exchange processes involving the doubly charged Higgs, whose existence is thus unmistakable if $\nonu$ decays are observed. The production and decays of the doubly charged Higgs are analyzed, and distinct and distinguishing signals are discussed.