Search for a light charged Higgs boson in t→H±b decays, with H±→cs, in pp collisions at s=13TeV with the ATLAS detector

Summary, in English

A search for a light charged Higgs boson produced in decays of the top quark, t→H±b with H±→cs, is presented. This search targets the production of top-quark pairs tt¯→WbH±b, with W→ℓν (ℓ=e,μ), resulting in a lepton-plus-jets final state characterised by an isolated electron or muon and at least four jets. The search exploits b-quark and c-quark identification techniques as well as multivariate methods to suppress the dominant tt¯ background. The data analysed correspond to 140fb-1 of pp collisions at s=13TeV recorded with the ATLAS detector at the LHC between 2015 and 2018. Observed (expected) 95% confidence-level upper limits on the branching fraction B(t→H±b), assuming B(t→Wb)+B(t→H±(→cs)b)=1.0, are set between 0.066% (0.077%) and 3.6% (2.3%) for a charged Higgs boson with a mass between 60 and 168 GeV. © The Author(s) 2025.

• Author: G. Aad; T.P.A. Åkesson; K.S.V. Astrand; C. Doglioni; P.A. Ekman; V. Hedberg; H. Herde; B. Konya; E. Lytken; R. Poettgen; O. Smirnova; E.J. Wallin; L. Zwalinski
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration; Department of Physics
• Publishing year: 2025
• Language: English
• Publication/Series: European Physical Journal C
• Volume: 85
• Issue: 2
• Links: http://dx.doi.org/10.1140/epjc/s10052-024-13715-4
• Document type: Journal article
• Publisher: Springer Nature
• Topic: Subatomic Physics
• Keywords: Charged particles; Colliding beam accelerators; Jets; ATLAS detectors; B-decays; Branching fractions; Confidence levels; Final state; Higgs boson; Identification techniques; Multivariate methods; Top quarks; Upper limits; Bosons
• Status: Published
• ISBN/ISSN/Other: ISSN: 1434-6044