2026/07/29 by ATLAS Collaboration
Physics and Astronomy · #hep-ex
32 pages in total, author list starting page 16, 4 figures, 1 table, submitted to PRL. All figures including auxiliary figures are available at: https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2025-05/
arxiv created 2026/07/29 · arxiv updated 2026/07/31
A search for heavy Majorana neutrinos coupling to third-generation leptons in vector boson scattering at the LHC is presented. The search is performed in the final state with a same-sign ττ, eτ or μτ pair using data of proton--proton collisions at √(s) = 13 TeV, recorded with the ATLAS detector and corresponding to an integrated luminosity of 140 fb-1. No significant deviation from the Standard Model background is observed. Constraints on the squared mixing matrix element between the τ-lepton and the heavy Majorana neutrino (|VτN|2) are derived for heavy Majorana neutrino masses between 92 GeV and 6.5 TeV. Additionally, two-dimensional constraints on (|VeN|2, |VτN|2) and (|VμN|2, |VτN|2) are set. These results improve the limits on heavy Majorana neutrinos coupling to third-generation leptons for heavy Majorana neutrino masses above 1.0 TeV, and extend the exclusion limits to an unexplored mass range above 1.5 TeV.