Experimental Sensitivity for Majorana Neutrinos Produced via a Z Boson at Hadron Colliders

TL;DR

This paper evaluates the potential for hadron colliders to detect or set limits on a hypothetical fourth-generation Majorana neutrino produced via Z boson decay, highlighting the sensitivity improvements over existing bounds.

Contribution

It provides the first experimental sensitivity estimates for Majorana neutrino production via Z boson decay at hadron colliders, including the Tevatron and LHC, for the first time.

Findings

Tevatron could extend mass limits to >175 GeV/c^2

LHC at 10 TeV could set limits >300 GeV/c^2

Potential for 3σ evidence if neutrino mass is below 150-225 GeV/c^2

Abstract

We present experimental sensitivity for the production of a fourth-generation Majorana neutrino ($N$) via an s-channel $Z$ boson $Z\to NN \to W\ell W\ell$ at hadron colliders. This channel has not been studied for the Tevatron dataset with $\int \mathcal{L}=5 $ fb$^{-1}$, where we find that a single experiment could significantly extend current 95% C.L. mass lower limits, to $m_N>175$ GeV$/c^2$, or report $3\sigma$ evidence for the $N$ if $m_N<150$ GeV$/c^2$. With 5 fb$^{-1}$, a single LHC experiment at $\sqrt{s}=10$ TeV could expect t o set a 95% C.L. mass lower limits of $m_N>300$ GeV$/c^2$, or report 3$\sigma$ evidence for the $N$ if $m_N<225$ GeV$/c^2$.