Constraints on fourth generation Majorana neutrinos

TL;DR

This paper explores the theoretical and experimental constraints on the existence of a fourth-generation Majorana neutrino, analyzing data from various decay processes and collider experiments to assess its viability.

Contribution

It provides a comprehensive analysis of constraints on a fourth-generation Majorana neutrino using recent experimental data and decay process studies.

Findings

Constraints from neutrinoless double beta decay are significant.

Limits from radiative lepton decay restrict parameter space.

Like-sign di-lepton production at colliders offers additional bounds.

Abstract

We investigate the possibility of a fourth sequential generation in the lepton sector. Assuming neutrinos to be Majorana particles and starting from a recent - albeit weak - evidence for a non-zero admixture of a fourth generation neutrino from fits to weak lepton and meson decays we discuss constraints from neutrinoless double beta decay, radiative lepton decay and like-sign di-lepton production at hadron colliders.