New Mechanism for Neutrino Mass Generation and Triply Charged Higgs Bosons at the LHC

TL;DR

This paper introduces a novel neutrino mass generation mechanism involving an isospin 3/2 Higgs multiplet, predicting triply charged Higgs bosons that could be detected at the LHC, offering insights into neutrino hierarchies and Higgs mass limits.

Contribution

It proposes a new dimension-seven operator-based neutrino mass mechanism with testable predictions for triply charged Higgs bosons at colliders.

Findings

Triply charged Higgs bosons can be produced at the LHC.

Decay modes of ^{+++} distinguish neutrino mass hierarchies.

Scenario allows Higgs mass to exceed 500 GeV.

Abstract

We propose a new mechanism for generating small neutrino masses which predicts the relation m_\nu ~ v^4/M^3, where v is the electroweak scale, rather than the conventional seesaw formula m_\nu ~ v^2/M. Such a mass relation is obtained via effective dimension seven operators LLHH(H*H)/M^3, which arise when an isospin 3/2 Higgs multiplet \Phi is introduced along with iso-triplet leptons. The masses of these particles are naturally in the TeV scale. The neutral member of \Phi acquires an induced vacuum expectation value and generates neutrino masses, while its triply charged partner provides the smoking gun signal of this scenario. These triply charged bosons can be pair produced at the LHC and the Tevatron, with \Phi^{+++} decaying into W^+l^+l^+ or W^+W^+W^+, possibly with displaced vertices. The leptonic decays of \Phi^{+++} will help discriminate between normal and inverted hierarchies of neutrino masses. This scenario also allows for raising the standard Higgs boson mass to values in excess of 500 GeV.