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Tomas Husek. Photo.

Tomas Husek

Postdoc

Tomas Husek. Photo.

Measurement of the very rare K + → π+νν¯ decay

Author

  • E. Cortina Gil
  • Tomáš Husek
  • P. Rubin

Summary, in English

The NA62 experiment reports the branching ratio measurement BR(K+→π+νν¯)=(10.6−3.4+4.0|stat±0.9syst)×10−11 at 68% CL, based on the observation of 20 signal candidates with an expected background of 7.0 events from the total data sample collected at the CERN SPS during 2016–2018. This provides evidence for the very rare K+→π+νν¯ decay, observed with a significance of 3.4σ. The experiment achieves a single event sensitivity of (0.839 ± 0.054) × 10−11, corresponding to 10.0 events assuming the Standard Model branching ratio of (8.4 ± 1.0) × 10−11. This measurement is also used to set limits on BR(K+→ π+X), where X is a scalar or pseudo-scalar particle. Details are given of the analysis of the 2018 data sample, which corresponds to about 80% of the total data sample. © 2021, The Author(s).

Department/s

  • Theoretical Particle Physics

Publishing year

2021

Language

English

Publication/Series

Journal of High Energy Physics

Volume

2021

Issue

6

Document type

Journal article

Publisher

Springer

Topic

  • Subatomic Physics

Keywords

  • FCNC Interaction
  • Fixed target experiments
  • Flavor physics
  • Flavour Changing Neutral Currents
  • Rare decay

Status

Published

ISBN/ISSN/Other

  • ISSN: 1029-8479