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


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Filmer E., Grant C., Green M., Jackson P., Kong A., Pandya H., ...More

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.