TY - JOUR
T1 - Search for heavy neutral lepton production in K+ decays to positrons
AU - The NA62 Collaboration
AU - Cortina Gil, E.
AU - Kleimenova, A.
AU - Minucci, E.
AU - Padolski, S.
AU - Petrov, P.
AU - Shaikhiev, A.
AU - Volpe, R.
AU - Numao, T.
AU - Petrov, Y.
AU - Velghe, B.
AU - Bryman, D.
AU - Fu, J.
AU - Husek, T.
AU - Jerhot, J.
AU - Kampf, K.
AU - Zamkovsky, M.
AU - Aliberti, R.
AU - Khoriauli, G.
AU - Kunze, J.
AU - Lomidze, D.
AU - Peruzzo, L.
AU - Vormstein, M.
AU - Wanke, R.
AU - Dalpiaz, P.
AU - Fiorini, M.
AU - Neri, I.
AU - Norton, A.
AU - Petrucci, F.
AU - Wahl, H.
AU - Cotta Ramusino, A.
AU - Gianoli, A.
AU - Iacopini, E.
AU - Latino, G.
AU - Lenti, M.
AU - Parenti, A.
AU - Bizzeti, A.
AU - Bucci, F.
AU - Antonelli, A.
AU - Georgiev, G.
AU - Kozhuharov, V.
AU - Lanfranchi, G.
AU - Martellotti, S.
AU - Moulson, M.
AU - Spadaro, T.
AU - Ambrosino, F.
AU - Capussela, T.
AU - Corvino, M.
AU - Di Filippo, D.
AU - Massarotti, P.
AU - Maurice, E.
N1 - Publisher Copyright:
© 2020 The Author(s)
PY - 2020/8/10
Y1 - 2020/8/10
N2 - A search for heavy neutral lepton (N) production in K+→e+N decays using the data sample collected by the NA62 experiment at CERN in 2017–2018 is reported. Upper limits of the extended neutrino mixing matrix element |Ue4|2 are established at the level of 10−9 over most of the accessible heavy neutral lepton mass range 144–462 MeV/c2, with the assumption that the lifetime exceeds 50 ns. These limits improve significantly upon those of previous production and decay searches. The |Ue4|2 range favoured by Big Bang Nucleosynthesis is excluded up to a mass of about 340 MeV/c2.
AB - A search for heavy neutral lepton (N) production in K+→e+N decays using the data sample collected by the NA62 experiment at CERN in 2017–2018 is reported. Upper limits of the extended neutrino mixing matrix element |Ue4|2 are established at the level of 10−9 over most of the accessible heavy neutral lepton mass range 144–462 MeV/c2, with the assumption that the lifetime exceeds 50 ns. These limits improve significantly upon those of previous production and decay searches. The |Ue4|2 range favoured by Big Bang Nucleosynthesis is excluded up to a mass of about 340 MeV/c2.
UR - https://www.scopus.com/pages/publications/85087480211
U2 - 10.1016/j.physletb.2020.135599
DO - 10.1016/j.physletb.2020.135599
M3 - Article
AN - SCOPUS:85087480211
SN - 0370-2693
VL - 807
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
M1 - 135599
ER -