Probing the existence of a new charged vector boson decaying into heavy neutral leptons using ultra-peripheral heavy ion collisions at ATLAS

TL;DR

This paper investigates the potential of ultra-peripheral heavy ion collisions at the LHC to discover or exclude new charged vector bosons decaying into heavy neutral leptons within the 5-100 GeV mass range, highlighting the unique sensitivity of ATLAS and HL-LHC.

Contribution

It introduces a novel search strategy using UPCs at ATLAS for detecting charged vector bosons and heavy neutral leptons, extending the mass range beyond previous experiments like LEP-II.

Findings

ATLAS can exclude certain mass scenarios at 95% C.L.

Discovery potential of 5σ for specific mass points at ATLAS.

HL-LHC can explore higher mass ranges and achieve 95% exclusion or 5σ discovery.

Abstract

In this paper we explore the potential of Ultra-peripheral Collisions in the LHC to investigate new physics, focusing specifically on the production of new charged vector bosons ${V}^{\pm}$ that decay into heavy neutral leptons $N_{L}$ in the context of the Vector Scotogenic Model. We show that the ATLAS experiment searching for dilepton+met final states through UPCs of lead ions, can prove the existence of new charged vector bosons in the mass range 5-100 GeV, a region not explored by the LEP-II experiment. Our analysis identifies regions in the parameter space where the signal can be distinguished from the background with high statistical significance. Within the mass range 5 GeV $<M_{V^{\pm}}, M_{N_L}<$ 100 GeV, ATLAS can exclude scenarios with 95\% of C.L. for specific mass scenarios such as (30 GeV, 20 GeV), (30 GeV, 10 GeV) and (20 GeV, 10 GeV). In a discovery context, ATLAS could reach a significance of 5$\sigma$ only for (20 GeV, 10 GeV). Furthermore, we show that in the absence of new physics signals at ATLAS, the High Luminosity LHC with UPCs of protons could explore further into larger mass ranges, specifically 100 GeV $< M_{V^{\pm}}<$ 200 GeV and 5 GeV $<M_{N_L}<$ 200 GeV. We find that the HL-LHC can exclude this mass range with 95\% of C.L., and most scenarios can achieve a discovery significance of 5$\sigma$