A potential scenario for the Majorana neutrino detection at future lepton colliders

TL;DR

This paper proposes a novel method to detect Majorana neutrinos at future lepton colliders by exploiting lepton-number violating processes, showing potential for improved sensitivity over previous experiments across various neutrino mass ranges.

Contribution

It introduces a new approach to search for Majorana neutrinos at electron-positron colliders using resonant production in lepton-number violating processes, with detailed sensitivity analysis.

Findings

CEPC can detect Majorana neutrinos in 5-80 GeV range more effectively than LEP2 or LHC.

ILC shows better sensitivity than LHC for neutrino masses above 250 GeV.

Resonant production at future colliders offers promising avenues for Majorana neutrino discovery.

Abstract

The existence of Majorana neutrinos must lead to lepton-number violating processes, and the Majorana nature of neutrinos can only be experimentally verified via lepton-number violating processes. We propose a new approach to search for Majorana neutrinos at future electron-positron colliders by exploiting this feature. We investigate the $\Delta L = 2$ like-sign dilepton production and find that lepton colliders with different center-of-mass energies have comparative advantages in resonant production of a Majorana neutrino in either light neutrino mass range or heavy mass range. At the future Circular Electron-Positron Collider (CEPC), with 250 GeV center-of-mass energy and 5 ab$^{-1}$ integrated luminosity, we find that there could be more significant sensitivity for resonant production of a Majorana neutrino in the mass range of 5-80 GeV than previous results at LEP2 or LHC. At the 1 TeV ILC with 1 ab$^{-1}$ integrated luminosity, it has better sensitivity than the similar process at LHC while the neutrino mass is larger than 250 GeV.