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.
Search for dark matter produced in association with a single top quark in √s=13 TeV pp collisions with the ATLAS detector / Aloisio, Alberto; Alviggi, Mariagrazia; Canale, Vincenzo; Della Pietra, Massimo; Merola, Leonardo; Massarotti, Paolo; Conventi, Francesco; Rossi, Elvira; Carlino, Giampaolo; de Asmundis, Riccardo; Di Donato, Camilla; Doria, Alessandra; Iengo, Paolo; Izzo, Vincenzo; Perrella, Sabrina; Sekhniaidze, Givi; Cirotto, Francesco; Lavorgna, Marco; Giannini, Antonio; Atlas, Collaboration. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 81:10(2021). [10.1140/epjc/s10052-021-09566-y]
Search for dark matter produced in association with a single top quark in √s=13 TeV pp collisions with the ATLAS detector
Aloisio, Alberto;Alviggi, MariaGrazia;Canale, Vincenzo;Della Pietra, Massimo;Merola, Leonardo;Massarotti, Paolo;Rossi, Elvira;Perrella, Sabrina;Cirotto, Francesco;Lavorgna, Marco;Giannini, Antonio;
2021
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.