Lepton Number Violation at the LHC in Radiative Neutrino Mass Models with Leptoquarks

Abstract

We investigate the prospects for observing lepton number violation (LNV) by two units, $|\Delta L| = 2$, at the LHC within the leptoquark variant of the Zee Model, where Majorana neutrino masses arise radiatively at one-loop. The model features an $SU(2)_L$ doublet and singlet leptoquarks, whose interactions produce a distinctive same-sign dilepton plus jets signature, $pp \to \ell^{\pm}\ell'^{\pm} + \text{jets}$. Taking into account current experimental constraints, we identify the dominant production channels for this LNV signal and perform a detailed collider analysis. We find that the HL-LHC can probe leptoquark masses up to $m_{\rm LQ} \sim 1.5~\mathrm{TeV}$ with this process. Observation of this signal would provide a direct test of LNV and would unambiguously establish the Majorana nature of neutrinos.