Search for heavy right-handed Majorana neutrinos in the decay of top quarks produced in proton-proton collisions at (Formula Presented) with the ATLAS detector
Physical Review D, vol.110, no.11, 2024 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 110 Issue: 11
- Publication Date: 2024
- Doi Number: 10.1103/physrevd.110.112004
- Journal Name: Physical Review D
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, INSPEC, zbMATH, Nature Index
- Open Archive Collection: Article
- Azerbaijan State University of Economics (UNEC) Affiliated: No
Abstract
A search for heavy right-handed Majorana neutrinos is performed with the ATLAS detector at the CERN Large Hadron Collider, using the (Formula Presented) of proton-proton collision data at (Formula Presented) collected during Run 2. This search targets (Formula Presented) production, in which both top quarks decay into a bottom quark and a (Formula Presented) boson, where one of the (Formula Presented) bosons decays hadronically and the other decays into an electron or muon and a heavy neutral lepton. The heavy neutral lepton is identified through a decay into an electron or muon and another (Formula Presented) boson, resulting in a pair of same-charge same-flavor leptons in the final state. This paper presents the first search for heavy neutral leptons in the mass range of 15-75 GeV using (Formula Presented) events. No significant excess is observed over the background expectation, and upper limits are placed on the signal cross sections. Assuming a benchmark scenario of the phenomenological type-I seesaw model, these cross section limits are then translated into upper limits on the mixing parameters of the heavy Majorana neutrino with Standard Model neutrinos.