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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Search for K+ decays to a muon and invisible particles
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 - Gatignon, L.
AU - Fry, J.R.
AU - Parkinson, C.
AU - Page, R.
AU - Britton, D.
AU - Graham, C.
AU - Carmignani, J.
AU - Dainton, J.B.
AU - Jones, R.W.L.
AU - Ruggiero, G.
AU - Cooper, P.
PY - 2021/5/10
Y1 - 2021/5/10
N2 - The NA62 experiment at CERN reports searches for K+→μ+N and K+→μ+νX decays, where N and X are massive invisible particles, using the 2016–2018 data set. The N particle is assumed to be a heavy neutral lepton, and the results are expressed as upper limits of O(10−8) of the neutrino mixing parameter |Uμ4|2 for N masses in the range 200–384 MeV/c2 and lifetime exceeding 50 ns. The X particle is considered a scalar or vector hidden sector mediator decaying to an invisible final state, and upper limits of the decay branching fraction for X masses in the range 10–370 MeV/c2 are reported for the first time, ranging from O(10−5) to O(10−7). An improved upper limit of 1.0×10−6 is established at 90% CL on the K+→μ+ννν¯ branching fraction.
AB - The NA62 experiment at CERN reports searches for K+→μ+N and K+→μ+νX decays, where N and X are massive invisible particles, using the 2016–2018 data set. The N particle is assumed to be a heavy neutral lepton, and the results are expressed as upper limits of O(10−8) of the neutrino mixing parameter |Uμ4|2 for N masses in the range 200–384 MeV/c2 and lifetime exceeding 50 ns. The X particle is considered a scalar or vector hidden sector mediator decaying to an invisible final state, and upper limits of the decay branching fraction for X masses in the range 10–370 MeV/c2 are reported for the first time, ranging from O(10−5) to O(10−7). An improved upper limit of 1.0×10−6 is established at 90% CL on the K+→μ+ννν¯ branching fraction.
U2 - 10.1016/j.physletb.2021.136259
DO - 10.1016/j.physletb.2021.136259
M3 - Journal article
VL - 816
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 - 136259
ER -