Search for K+ decays into the π+e+e−e+e− final state


Cortina Gil, E ORCID: 0000-0001-9627-699X, Kleimenova, A ORCID: 0000-0002-9129-4985, Minucci, E ORCID: 0000-0002-3972-6824, Padolski, S ORCID: 0000-0002-6795-7670, Petrov, P, Shaikhiev, A ORCID: 0000-0003-2921-8743, Volpe, R ORCID: 0000-0003-1782-2978, Numao, T ORCID: 0000-0001-5232-6190, Petrov, Y ORCID: 0000-0003-2643-8740, Velghe, B ORCID: 0000-0002-0797-8381 et al (show 222 more authors) (2023) Search for K+ decays into the π+e+e−e+e− final state. Physics Letters B, 846. p. 138193.

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Abstract

The first search for ultra-rare K+ decays into the π+e+e−e+e− final state is reported, using a dataset collected by the NA62 experiment at CERN in 2017–2018. An upper limit of 1.4×10−8 at 90% CL is obtained for the branching ratio of the K+→π+e+e−e+e− decay, predicted in the Standard Model to be (7.2±0.7)×10−11. Upper limits at 90% CL are obtained at the level of 10−9 for the branching ratios of two prompt decay chains involving pair-production of hidden-sector mediators: K+→π+aa, a→e+e− and K+→π+S, S→A′A′, A′→e+e−.

Item Type: Article
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 30 Nov 2023 12:00
Last Modified: 30 Nov 2023 12:03
DOI: 10.1016/j.physletb.2023.138193
Open Access URL: https://www.sciencedirect.com/science/article/pii/...
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3177081
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