Heavy majorana neutrino pair production from Z' at hadron and lepton colliders

Abstract

A gauged U(1) extension of the Standard Model (SM) is a simple and anomaly-free framework wherethree generations of Majorana type right-handed neutrinos (RHNs) are introduced to generate light neutrinomass and flavor mixings through the seesaw mechanism. We investigate such models at different hadronand lepton colliders viaZ0induced Majorana type RHNs pair production. We derive bounds on U(1) gaugecouplingðg0Þcomparing the model cross sections with experimentally observed data for differentZ0massðMZ0Þand RHNs massðMNÞ. Using these limits we estimate the allowed RHN pair production crosssection which can be manifested by lepton number violating signatures in association with fat-jets at thehadron colliders depending on the mass of the RHNs. Hence we study dilepton and trilepton modes withfat-jet/s of the signal for different benchmark values ofMZ0andMN. Using fat-jet signatures and studyingthe signal and corresponding SM backgrounds, we estimate bounds onMN-MZ0plane at different center ofmass energies which could be probed at different hadron colliders. In the context of the lepton colliders weconsider electron positron initial states where Majorana type RHNs can be produced fromZ0manifestingsame sign dilepton plus jets signature and trilepton plus jets in association with missing energy. Studyingthe signal and corresponding SM backgrounds we estimate the bounds on theMN-MZ0plane for differentcenter of mass energies. In the context of the U(1) extension of the SM there is a SM singlet BSM scalarwhich couples with the RHNs. We can probe the Majorana nature of RHNs via this BSM scalar productionat electron positron colliders.