Probing Lepton Number Violation and Majorana Nature of Neutrinos at the LHC

TL;DR

This paper investigates the potential to detect lepton number violation and the Majorana nature of neutrinos at the LHC within the type-II seesaw and Zee models, focusing on same-sign lepton signals and their sensitivity limits.

Contribution

It provides the first detailed sensitivity analysis for lepton number violation signals in these two neutrino mass models at the high-luminosity LHC.

Findings

Sensitivity to lepton number violation up to 700 GeV in the type-II seesaw model.

Sensitivity to charged scalar masses up to 4.8 TeV in the Zee model.

Potential to observe L-violation signals with 3 ab^{-1} luminosity.

Abstract

Observation of lepton number ($L$) violation by two units at colliders would provide evidence for the Majorana nature of neutrinos. We study signals of $L$-violation in the context of two popular models of neutrino masses, the type-II seesaw model and the Zee model, wherein small neutrino masses arise at the tree-level and one-loop level, respectively. We focus on $L$-violation signals at the LHC arising through the process $pp \to \ell^{\pm}\ell^{\prime \pm}$ + jets within these frameworks. We obtain sensitivity to $L$-violation in the type-II seesaw model for triplet scalar masses up to 700 GeV and in the Zee model for charged scalar masses up to 4.8 TeV at the high-luminosity LHC with an integrated luminosity of $3~\text{ab}^{-1}$.