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

We investigate the prospects for observing lepton number violation (LNV) by two units, $\mathrm{\mid }\mathrm{\Delta }L\mathrm{\mid }=2$, 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, $pp\to {\mathrm{\ell }}^{\pm }{\mathrm{\ell }}^{\mathrm{\prime }\pm }+\text{jets}$. 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 $m_{\mathrm{L}\mathrm{Q}}\sim 1.5\mathrm{T}\mathrm{e}\mathrm{V}$ with this process. Observation of this signal would provide a direct test of LNV and would unambiguously establish the Majorana nature of neutrinos.