LHC as a photon-photon collider: bounds on $\Gamma_{X\to\gamma\gamma}$

TL;DR

This paper uses LHC data on muon pair production in ultraperipheral proton collisions to set bounds on a potential 28 GeV resonance's coupling to photons, providing a new method for future searches.

Contribution

It introduces a novel approach to constrain photon couplings of low-mass resonances using existing LHC data on muon pairs in UPCs.

Findings

Established an upper bound on the resonance's gamma-gamma coupling.

Demonstrated the method's applicability for future resonance searches.

Provided constraints relevant for models predicting such a resonance.

Abstract

In the relatively recent CMS data, there is a hint on the existence of a resonance with the mass 28 GeV coupling to muons. Such a resonance should also couple to photons through the fermion loop, therefore it can be searched for in ultraperipheral collisions (UPC) of protons. We set an upper bound on the $X \gamma \gamma$ coupling constant from the data on $\mu^+ \mu^-$ pair production in UPC at the LHC. Our approach can be used for similar resonances should they appear in the future.