Physics Letters B, Vol 872, Iss , Pp 140119- (2026)
Publisher Information:
Elsevier
Publication Year:
2026
Collection:
Directory of Open Access Journals: DOAJ Articles
Subject Terms:
Physics; QC1-999
Description:
A search for heavy neutral lepton (N) production in π+→e+N in-flight decays using data collected by the NA62 experiment at CERN in 2017–2024 is reported. Upper limits for the extended neutrino mixing matrix element |Ue4|2 are established at the level of 10−8 for heavy neutral leptons with mass in the range 95–126 MeV/c2 and lifetime exceeding 50 ns.