Searches for lepton number violating $K^+\to\pi^-(\pi^0)e^+e^+$ decays

Cortina Gil, Eduardo; Minucci, Elisa; Padolski, Sergey; Petrov, Plamen; Velghe, Bob; Bryman, Douglas; Fu, Ji; Numao, Toshio; Petrov, Yevgeniy; Wong, Vincent Wai Sum

doi:10.1016/j.physletb.2022.137172

Searches for lepton number violating $K^+\to\pi^-(\pi^0)e^+e^+$ decays

NA62

Collaboration

Feb 1, 2022

16 pages

Published in:

Phys.Lett.B 830 (2022) 137172

Published: Jul 10, 2022

e-Print:

2202.00331 [hep-ex]

DOI:

10.1016/j.physletb.2022.137172 (publication)

PDG:

{{\mathit K}^{+}}

\rightarrow

{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}{{\mathit e}^{+}}{{\mathit e}^{+}}

Report number:

CERN-EP-2022-018

Experiments:

CERN-NA-062

View in:

pdf

reference search40 citations

Citations per year

Abstract: (Elsevier B.V.)

Searches for lepton number violating

K^{+} \to π^{-} e^{+} e^{+}

and

K^{+} \to π^{-} π^{0} e^{+} e^{+}

decays have been performed using the complete dataset collected by the NA62 experiment at CERN in 2016–2018. Upper limits of

5.3 \times 10^{- 11}

and

8.5 \times 10^{- 10}

are obtained on the decay branching fractions at 90% confidence level. The former result improves by a factor of four over the previous best limit, while the latter result represents the first limit on the

K^{+} \to π^{-} π^{0} e^{+} e^{+}

decay rate.

Note:

Updated version (8 May 2022) accepted for publication in Physics Letters B

K+: secondary beam
K+: semileptonic decay
K+: rare decay
positron
lepton number: violation
CERN Lab
K+: decay rate
NA62
CERN SPS
K+: branching ratio

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Searches for lepton number violating K+→π−(π0)e+e+K^+\to\pi^-(\pi^0)e^+e^+K+→π−(π0)e+e+ decays

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Searches for lepton number violating $K^+\to\pi^-(\pi^0)e^+e^+$ decays