Search for a new Z′ gauge boson in 4μ events with the ATLAS experiment


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Aad G., Abbott B., Abbott D., Abeling K., Abidi S., Aboulhorma A., ...More

Journal of High Energy Physics, vol.2023, no.7, 2023 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 2023 Issue: 7
  • Publication Date: 2023
  • Doi Number: 10.1007/jhep07(2023)090
  • Journal Name: Journal of High Energy Physics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, INSPEC, zbMATH, Directory of Open Access Journals
  • Keywords: Beyond Standard Model, Hadron-Hadron Scattering
  • Ankara University Affiliated: Yes

Abstract

This paper presents a search for a new Z′ vector gauge boson with the ATLAS experiment at the Large Hadron Collider using pp collision data collected at s = 13 TeV, corresponding to an integrated luminosity of 139 fb −1. The new gauge boson Z′ is predicted by Lμ − Lτ models to address observed phenomena that can not be explained by the Standard Model. The search examines the four-muon (4μ) final state, using a deep learning neural network classifier to separate the Z′ signal from the Standard Model background events. The di-muon invariant masses in the 4μ events are used to extract the Z′ resonance signature. No significant excess of events is observed over the predicted background. Upper limits at a 95% confidence level on the Z′ production cross-section times the decay branching fraction of pp → Z′μμ → 4μ are set from 0.31 to 4.3 fb for the Z′ mass ranging from 5 to 81 GeV. The corresponding common coupling strengths, gZ′, of the Z′ boson to the second and third generation leptons above 0.003 – 0.2 have been excluded. [Figure not available: see fulltext.].