Search for dark matter produced in association with a single top quark in √s=13 TeV pp collisions with the ATLAS detector

Summary, in English

This paper presents a search for dark matter in the context of a two-Higgs-doublet model together with an additional pseudoscalar mediator, a, which decays into the dark-matter particles. Processes where the pseudoscalar mediator is produced in association with a single top quark in the 2HDM+a model are explored for the first time at the LHC. Several final states which include either one or two charged leptons (electrons or muons) and a significant amount of missing transverse momentum are considered. The analysis is based on proton–proton collision data collected with the ATLAS experiment at s=13 TeV during LHC Run 2 (2015–2018), corresponding to an integrated luminosity of 139 fb - 1. No significant excess above the Standard Model predictions is found. The results are expressed as 95% confidence-level limits on the parameters of the signal models considered. © 2021, The Author(s).

• Author: G Aad; Torsten Åkesson; Simona Bocchetta; Eric Edward Corrigan; Caterina Doglioni; Jannik Geisen; Kristian Gregersen; Eva Brottmann Hansen; Vincent Hedberg; Göran Jarlskog; Edgar Kellermann; Balazs Konya; Else Lytken; Katja Mankinen; Caterina Marcon; Ulf Mjörnmark; Geoffrey André Adrien Mullier; Ruth Pöttgen; Trine Poulsen; Eleni Skorda; Oxana Smirnova; L Zwalinski
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2021
• Language: English
• Publication/Series: European Physical Journal C
• Volume: 81
• Issue: 10
• Links: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85116501953&doi=10.1140%2fepjc%2fs10052-021-09566-y&partnerID=40&md5=bcde294a888f48151aa14e2cae0f0e4a; http://dx.doi.org/10.1140/epjc/s10052-021-09566-y
• Document type: Journal article
• Publisher: Springer Nature
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1434-6044