# Searches for lepton flavour and lepton number violation in K<sup>+</sup> decays at NA62

Swallow, J, Aliberti, R, Ambrosino, F, Ammendola, R, Angelucci, B, Antonelli, A, Anzivino, G, Arcidiacono, R, Bache, T, Baeva, A
et al (show 90 more authors) (2021) Searches for lepton flavour and lepton number violation in K<sup>+</sup> decays at NA62. .

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## Abstract

A search for the lepton number violating K+ ? p-µ+e+ and lepton flavour violating K+ ? p-µ-e+ decays is reported using NA62 data collected in 2017 and 2018. No significant excess is observed above the background expectation and therefore upper limits are established on the branching ratios at 90% confidence level: B(K+ ? p-µ+e+) < 4.2 × 10-11 and B(K+ ? p+µ-e+) < 6.6 × 10-11. These results improve over the previous limits by factors of 12 and 8 respectively.

Item Type: Conference or Workshop Item (Unspecified) Faculty of Science and Engineering > School of Physical Sciences Symplectic Admin 17 Dec 2021 16:06 29 Jun 2022 09:31 https://pos.sissa.it/390/430/pdf https://livrepository.liverpool.ac.uk/id/eprint/3145584