Search for long-lived heavy neutrinos in the decays of B mesons produced in proton-proton collisions at s√ = 13 TeV

(CMS Collaboration) Hayrapetyan, Aram ; ... ; Giljanović, Duje ; Godinović, Nikola ; Lelas, Damir ; Šćulac, Ana ; Kovač, Marko ; Petković, Andro ; Šćulac, Toni ; Bargassa, Pedrame ; Brigljević, Vuko ; Chitroda, Bhakti Kanulal ; Ferenček, Dinko ; Jakovčić, Krešimir ; Mishra, Saswat ; Starodumov, Andrey ; Šuša, Tatjana ; ... ; Roguljić, Matej ; ... ; Zhokin, Alexander (2024) Search for long-lived heavy neutrinos in the decays of B mesons produced in proton-proton collisions at s√ = 13 TeV. Journal of High Energy Physics, 2024 (6). ISSN 1126-6708

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Abstract

A search for long-lived heavy neutrinos (N) in the decays of B mesons produced in proton-proton collisions at s√ = 13 TeV is presented. The data sample corresponds to an integrated luminosity of 41.6 fb−1 collected in 2018 by the CMS experiment at the CERN LHC, using a dedicated data stream that enhances the number of recorded events containing B mesons. The search probes heavy neutrinos with masses in the range 1 < mN < 3 GeV and decay lengths in the range 10−2 < cτN < 104 mm, where τN is the N proper mean lifetime. Signal events are defined by the signature B → ℓBNX; N → ℓ±π∓, where the leptons ℓB and ℓ can be either a muon or an electron, provided that at least one of them is a muon. The hadronic recoil system, X, is treated inclusively and is not reconstructed. No significant excess of events over the standard model background is observed in any of the ℓ±π∓ invariant mass distributions. Limits at 95% confidence level on the sum of the squares of the mixing amplitudes between heavy and light neutrinos, |VN|2, and on cτ are obtained in different mixing scenarios for both Majorana and Dirac-like N particles. The most stringent upper limit |VN|2 < 2.0 × 10−5 is obtained at mN = 1.95 GeV for the Majorana case where N mixes exclusively with muon neutrinos. The limits on |VN|2 for masses 1 < mN < 1.7 GeV are the most stringent from a collider experiment to date.

Item Type:	Article
Uncontrolled Keywords:	High energy physics ; Experimental particle physics ; LHC ; CMS ; Beyond Standard Model ; Hadron-Hadron Scattering ; Lifetime ; p p colliding beams ; heavy neutrino ; p p scattering ; B semileptonic decay ; hadronic recoil ; muon ; neutrino mass ; neutrino mixing ; neutral particle ; Majorana ; Dirac ; CERN Lab ; electron ; many-body problem ; lepton ; CERN LHC Coll ; background ; mass spectrum ; (lepton pi)
Subjects:	NATURAL SCIENCES > Physics NATURAL SCIENCES > Physics > Physics of Elementary Particles and Fields
Divisions:	Division of Experimental Physics
Depositing User:	Sanja Jurković
Date Deposited:	09 Oct 2024 11:36
URI:	http://fulir.irb.hr/id/eprint/9154
DOI:	10.1007/JHEP06(2024)183

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