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



Aad, G, Abbott, B, Abbott, DC, Abeling, K, Abidi, SH, Aboulhorma, A, Abramowicz, H, Abreu, H, Abulaiti, Y, Abusleme Hoffman, AC
et al (show 2889 more authors) (2023) Search for a new <i>Z</i>′ gauge boson in 4μ events with the ATLAS experiment. JOURNAL OF HIGH ENERGY PHYSICS, 2023 (7). 90-.

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Abstract

<jats:title>A<jats:sc>bstract</jats:sc> </jats:title><jats:p>This paper presents a search for a new <jats:italic>Z</jats:italic>′ vector gauge boson with the ATLAS experiment at the Large Hadron Collider using <jats:italic>pp</jats:italic> collision data collected at <jats:inline-formula><jats:alternatives><jats:tex-math>$$ \sqrt{s} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math></jats:alternatives></jats:inline-formula> = 13 TeV, corresponding to an integrated luminosity of 139 fb<jats:sup><jats:italic>−</jats:italic>1</jats:sup>. The new gauge boson <jats:italic>Z</jats:italic>′ is predicted by <jats:italic>L</jats:italic><jats:sub><jats:italic>μ</jats:italic></jats:sub> − <jats:italic>L</jats:italic><jats:sub><jats:italic>τ</jats:italic></jats:sub> models to address observed phenomena that can not be explained by the Standard Model. The search examines the four-muon (4<jats:italic>μ</jats:italic>) final state, using a deep learning neural network classifier to separate the <jats:italic>Z</jats:italic>′ signal from the Standard Model background events. The di-muon invariant masses in the 4<jats:italic>μ</jats:italic> events are used to extract the <jats:italic>Z</jats:italic>′ resonance signature. No significant excess of events is observed over the predicted background. Upper limits at a 95% confidence level on the <jats:italic>Z</jats:italic>′ production cross-section times the decay branching fraction of <jats:italic>pp → Z</jats:italic>′<jats:italic>μμ →</jats:italic> 4<jats:italic>μ</jats:italic> are set from 0.31 to 4.3 fb for the <jats:italic>Z</jats:italic>′ mass ranging from 5 to 81 GeV. The corresponding common coupling strengths, <jats:italic>g</jats:italic><jats:sub><jats:italic>Z</jats:italic>′</jats:sub>, of the <jats:italic>Z</jats:italic>′ boson to the second and third generation leptons above 0.003 – 0.2 have been excluded.</jats:p>

Item Type: Article
Uncontrolled Keywords: Beyond Standard Model, Hadron-Hadron Scattering
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 09 Aug 2023 10:22
Last Modified: 18 Mar 2024 03:49
DOI: 10.1007/JHEP07(2023)090
Open Access URL: https://link.springer.com/article/10.1007/JHEP07(2...
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3172101