$\ge 4 \mu$ signal from a vector-like lepton decaying to a muon-philic $Z^\prime$ boson at the LHC

TL;DR

This paper proposes a new LHC search for signals with more than four muons from vector-like leptons decaying to a muon-philic Z' boson, which could explain muon anomalies and is testable at future colliders.

Contribution

It introduces a novel multi-muon signal from vector-like leptons decaying to a Z' boson, linking collider searches to muon anomaly explanations and exploring future detection prospects.

Findings

Current LHC data exclude certain vector-like lepton masses and branching ratios.

A scenario with a 400 GeV singlet vector-like lepton explains excess events with over five leptons.

Future HL-LHC runs could probe this model further.

Abstract

We propose a novel possibility to detect a very distinctive signal with more than four muons originating from pair-produced vector-like leptons decaying to a muon-philic $Z^\prime$ boson. These new particles are good candidates to explain the anomalies in the muon anomalous magnetic moment and the $b\to s\ell\ell$ processes. The doublet (singlet) vector-like leptons lighter than 1.3 (1.0) TeV are excluded by the latest data at the LHC if $\mathrm{BR}(E\to Z^\prime \mu) = 1$. We also show that the excess in the signal region with more than five leptons can be explained by this scenario if the vector-like lepton is a weak singlet, with mass about 400 GeV and $\mathrm{BR}(E\to Z^\prime \mu) = 0.25$. The future prospects at the HL-LHC are discussed.