Majorana neutrinos production at LHeC in an effective approach

TL;DR

This paper explores the potential to detect Majorana neutrinos at the LHeC collider using an effective Lagrangian approach, identifying signatures and discovery prospects for neutrino masses up to 700-1300 GeV.

Contribution

It introduces an effective field theory framework to analyze Majorana neutrino production at the LHeC and evaluates the collider's discovery reach based on various parameters.

Findings

LHeC can potentially discover Majorana neutrinos below 700 GeV at 50 GeV electron energy.

Discovery reach extends to 1300 GeV with 150 GeV electron energy.

Clear signatures involve lepton number violation with specific final states.

Abstract

We investigate the possibility of detecting Majorana neutrinos at the Large Hadron-electron Collider (LHeC), an electron-proton collision mode at CERN. We study the $l_j^{+} + 3 jets$ ($l_j\equiv e ,\mu ,\tau$) final states which are, due to leptonic number violation, a clear signature for intermediate Majorana neutrino contributions. Such signals are not possible if the heavy neutrinos have Dirac nature. The interactions between Majorana neutrinos and the Standard Model (SM) particles are obtained from an effective lagrangian approach. We present our results for the total cross section as a function of the neutrino mass, the effective couplings and the new physics scale. We also show the discovery region as a function of the Majorana neutrino mass and the effective couplings. Our results show that the LHeC may be able to discover Majorana neutrinos with masses lower than $700$ GeV and $1300$ GeV for electron beams settings of $E_e=50$ GeV and $E_e=150$ GeV, respectively.