Search for an axion-like particle with forward proton scattering in association with photon pairs at ATLAS

• Author(s): Castro, Nuno Filipe ; Onofre, A. ; ATLAS Collaboration
• Date: 2023
• Persistent ID: https://hdl.handle.net/1822/87813
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): CP Violation; Hadron-Hadron Scattering
• Document Type: Journal article
• Language: English
• Contributor(s): Universidade do Minho

Description

A search for forward proton scattering in association with light-by-light scattering mediated by an axion-like particle is presented, using the ATLAS Forward Proton spectrometer to detect scattered protons and the central ATLAS detector to detect pairs of outgoing photons. Proton-proton collision data recorded in 2017 at a centre-of-mass energy of s = 13 TeV were analysed, corresponding to an integrated luminosity of 14.6 fb −1. A total of 441 candidate events were selected. A search was made for a narrow resonance in the diphoton mass distribution, corresponding to an axion-like particle (ALP) with mass in the range 150–1600 GeV. No excess is observed above a smooth background. Upper limits on the production cross section of a narrow resonance are set as a function of the mass, and are interpreted as upper limits on the ALP production coupling constant, assuming 100% decay branching ratio into a photon pair. The inferred upper limit on the coupling constant is in the range 0.04–0.09 TeV −1 at 95% confidence level. [Figure not available: see fulltext.]