002946844 001__ 2946844
002946844 005__ 20251023214007.0
002946844 0248_ $$aoai:cds.cern.ch:2946844$$pcerncds:FULLTEXT
002946844 037__ $$aPoster-2025-1260
002946844 041__ $$aeng
002946844 100__ $$0AUTHOR|(CDS)2887433$$aCollaviti, Spencer$$mspencer.edward.collaviti@cern.ch$$uEPFL - Ecole Polytechnique Federale Lausanne (CH)
002946844 245__ $$aHeavy Neutral Lepton Searches at the LHCb Experiment
002946844 260__ $$c2025
002946844 269__ $$aGeneva$$bCERN$$c20 Oct 2025
002946844 270__ $$mspencer.edward.collaviti@cern.ch
002946844 300__ $$a1 p
002946844 520__ $$aHeavy Neutral Leptons (HNLs) are hypothetical long-lived particles that extend the Standard Model (SM) and provide a natural explanation for the non-zero neutrino masses. In addition, they could play a key role in addressing some of the most profound open questions in particle physics and cosmology, including the origin of the matter–antimatter asymmetry via baryogenesis. In this poster, we present the status and state-of-the-art of HNL searches at the LHCb experiment. We report the latest and most stringent LHCb limits on muon-coupled HNLs in the 1.6–5 GeV mass range, obtained from a Run 2 (2016–2018) analysis targeting displaced vertices corresponding to HNL flight distances of 0.02–0.5 m. Looking ahead, for Run 3 we introduce a novel reconstruction technique that exploits track segments downstream of the LHCb magnet, thereby extending the accessible displacement window to 0.5–8.0 m. This approach enhances sensitivity dramatically, providing a 40-fold increase in the number of accessible HNL events and extending the lifetime reach by a factor of 16 compared to the Run 2 analysis. A dedicated sensitivity study shows how these improvements translate into a significantly extended reach in the HNL mass–coupling parameter space, positioning LHCb to set world-leading constraints on HNLs.
002946844 595__ $$aCERN EDS
002946844 690C_ $$aCERN
002946844 693__ $$eLHCb
002946844 710__ $$5EP
002946844 8564_ $$qhttps://cds.cern.ch/record/2946844/files/$$xicon
002946844 8564_ $$82790663$$s1103544$$uhttps://cds.cern.ch/record/2946844/files/Poster-2025-1260.pdf
002946844 8564_ $$82790663$$s82128$$uhttps://cds.cern.ch/record/2946844/files/Poster-2025-1260.gif?subformat=icon$$xicon
002946844 859__ $$flhcb.secretariat@cern.ch
002946844 960__ $$a80
002946844 980__ $$aPOSTER