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.
Original language | English |
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Article number | 90 |
Number of pages | 42 |
Journal | JHEP |
Volume | 2023 |
DOIs | |
Publication status | Published - 12 Jul 2023 |
Bibliographical note
25 pages in total, without author list, 7 figures, 3 tables, submitted to JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HDBS-2018-57/
Keywords
- hep-ex