Extra Higgs Boson and $Z^{\mathrm{\prime }}$ as Portals to Signatures of Heavy Neutrinos at the LHC

In this paper, we discuss the potential of observing heavy neutrino (${\nu }_h$) signatures of a $U(1{)}_{B-L}$ enlarged Standard Model (SM) encompassing three heavy Majorana neutrinos alongside the known light neutrino states at the Large Hadron Collider (LHC). We exploit the theoretical decay via a pair of heavy (non-SM-like) Higgs boson and $Z^{\mathrm{\prime }}$ production followed by $\nu_h \rightarrow l^\pm W^{\mp ()}$and$\nu_h \rightarrow \nu_l Z^{()}$ decays, ultimately yielding a $3l+2j+E_T^{\mathrm{m}\mathrm{i}\mathrm{s}\mathrm{s}}$ signature and, depending upon how boosted the final state objects are, we define different possible selections aimed at improving the signal to background ratio in LHC Run 2 data for a wide range of heavy neutrino masses.