Search for lepton number and flavour violation in K+ and π0 decays

Volpe, R; Akmete, A; Aliberti, R; Ambrosino, F; Ammendola, R; Angelucci, B; Antonelli, A; Anzivino, G; Arcidiacono, R; Bache, T; Baeva, A; Baigarashev, D; Bandiera, L; Barbanera, M; Bern-Hard, J; Biagioni, A; Bician, L; Biino, C; Bizzeti, A; Blazek, T; Bloch-Devaux, B; Boboc, P; Bonaiuto, V; Boretto, M; Bragadireanu, M; Brianoolvera, A; Britton, D; Brizioli, F; Brunetti, Mb; Bryman, D; Bucci, F; Capussela, T; Carmignani, J; Ceccucci, A; Cenci, P; Cerny, V; Cerri, C; Checcucci, B; Conovaloff, A; Cooper, P; Gil, Ec; Corvino, M; Costantini, F; Ramusino, Ac; Coward, D; D'Agostini, G; Dainton, J; Dalpiaz, P; Danielsson, H; D'Errico, M; Desimone, N; Difilippo, D; Dilella, L; Doble, N; Dobrich, B; Duval, F; Duk, V; Emelyanov, D; Engelfried, J; Enik, T; Estrada-Tristan, N; Falaleev, V; Fantechi, R; Fascianelli, V; Federici, L; Fedotov, S; Filippi, A; Fiorenza, R; Fiorini, M; Fry, J; Fu, J; Fucci, A; Fulton, L; Gamberini, E; Gatignon, L; Georgiev, G; Ghinescu, S; Gianoli, A; Giorgi, M; Giudici, S; Gonnella, F; Gorshanov, K; Goudzovski, E; Graham, C; Guida, R; Gushchin, E; Hahn, F; Heath, H; Henshaw, J; Hives, Z; Holzer, Eb; Husek, T; Hutanu, O; Hutchcroft, D; Iacobuzio, L; Iacopini, E; Imbergamo, E; Jenninger, B; Jerhot, J; Jones, Rw; Kampf, K; Kekelidze, V; Kerebay, D; Kholodenko, S; Khoriauli, G; Khotyantsev, A; Kleimenova, A; Korotkova, A; Koval, M; Kozhuharov, V; Kucerova, Z; Kudenko, Y; Kunze, J; Kurochka, V; Kurshetsov, V; Lanfranchi, G; Lamanna, G; Lari, E; Latino, G; Laycock, P; Lazzeroni, C; Lenti, M; Lehmannmiotto, G; Leonardi, E; Lichard, P; Litov, L; Lochiatto, P; Lollini, R; Lomidze, D; Lonardo, A; Lubrano, P; Lupi, M; Lurkin, N; Madigozhin, D; Mannelli, I; Mapelli, A; Marchetto, F; Marchevski, R; Martellotti, S; Massarotti, P; Massri, K; Maurice, E; Mazzolari, A; Medvedeva, M; Mefodev, A; Menichetti, E; Migliore, E; Minucci, E; Mirra, M; Misheva, M; Molokanova, N; Moulson, M; Movchan, S; Napolitano, M; Neri, I; Newson, F; Norton, A; Noy, M; Numao, T; Obraztsov, V; Okhotnikov, A; Ostankov, A; Padolski, S; Page, R; Palladino, V; Panichi, I; Parenti, A; Parkinson, C; Pedreschi, E; Pepe, M; Perrin-Terrin, M; Peruzzo, L; Petrov, P; Petrov, Y; Petrucci, F; Piandani, R; Piccini, M; Pinzino, J; Polenkevich, I; Pontisso, L; Potrebenikov, Y; Protopopescu, D; Raggi, M; Reyessantos, M; Romagnoni, M; Romano, A; Rubin, P; Ruggiero, G; Ryjov, V; Sadovsky, A; Salamon, A; Santoni, C; Saracino, G; Sargeni, F; Schuchmann, S; Semenov, V; Sergi, A; Shaikhiev, A; Shkarovskiy, S; Soldani, M; Soldi, D; Sozzi, M; Spadaro, T; Spinella, F; Sturgess, A; Sugonyaev, V; Swallow, J; Sytov, A; Tinti, G; Tomczak, A; Trilov, S; Valente, P; Velghe, B; Venditti, S; Vicini, P; Volpe, R; Vormstein, M; Wahl, H; Wanke, R; Wong, V; Wrona, B; Yushchenko, O; Zamkovsky, M; Zinchenko, A

doi:10.22323/1.380.0426

The NA62 experiment at CERN collected a large sample of charged kaon decays into final states with multiple charged particles in 2016-2018. This sample provides sensitivities to rare decays with branching ratios as low as 10−11. Searches for the lepton number violating K+ → π−µ+e+ decay and the lepton flavour violating K+ → π+µ−e+ and π0 → µ−e+ decays are reported. No evidence for these decays is found and upper limits of the branching ratios are obtained at 90% confidence level. These results improve by one order of magnitude over previous results for these decay modes.

Volpe, R., Akmete, A., Aliberti, R., Ambrosino, F., Ammendola, R., Angelucci, B., et al. (2022). Search for lepton number and flavour violation in K+ and π0 decays. In Proceedings of Science. Sissa Medialab Srl [10.22323/1.380.0426].