# Broadening the Higgs Boson with Right-Handed Neutrinos and a Higher Dimension Operator at the Electroweak Scale

## TL;DR

This paper explores how higher-dimension operators at the electroweak scale can enable new Higgs decay channels into right-handed neutrinos, leading to distinctive collider signatures like displaced vertices, with implications for flavor symmetries and experimental constraints.

## Contribution

It introduces a novel analysis of Higgs decays into right-handed neutrinos via higher-dimension operators, considering flavor symmetries and collider signatures.

## Key findings

- New decay channels can dominate for light Higgs bosons.
- Right-handed neutrinos produce displaced vertices with lepton number violation.
- Decay modes depend on flavor symmetry assumptions.

## Abstract

The existence of certain TeV suppressed higher-dimension operators may open up new decay channels for the Higgs boson to decay into lighter right-handed neutrinos. These channels may dominate over all other channels if the Higgs boson is light. For a Higgs boson mass larger than $2 m_W$ the new decays are subdominant yet still of interest. The right-handed neutrinos have macroscopic decay lengths and decay mostly into final states containing leptons and quarks. A distinguishing collider signature of this scenario is a pair of displaced vertices violating lepton number. A general operator analysis is performed using the minimal flavor violation hypothesis to illustrate that these novel decay processes can occur while remaining consistent with experimental constraints on lepton number violating processes. In this context the question of whether these new decay modes dominate is found to depend crucially on the approximate flavor symmetries of the right-handed neutrinos.