Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Search for K+ decays to a muon and invisible particles

Cortina Gil, E. and Husek, T. LU (2021) In Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 816.
Abstract

The NA62 experiment at CERN reports searches for K+→μ+N and K+→μ+νX decays, where N and X are massive invisible particles, using the 2016–2018 data set. The N particle is assumed to be a heavy neutral lepton, and the results are expressed as upper limits of O(10−8) of the neutrino mixing parameter |Uμ4|2 for N masses in the range 200–384 MeV/c2 and lifetime exceeding 50 ns. The X particle is considered a scalar or vector hidden sector mediator decaying to an invisible final state, and upper limits of the decay branching fraction for X masses in the range 10–370 MeV/c2 are reported for the first time, ranging from O(10−5) to... (More)

The NA62 experiment at CERN reports searches for K+→μ+N and K+→μ+νX decays, where N and X are massive invisible particles, using the 2016–2018 data set. The N particle is assumed to be a heavy neutral lepton, and the results are expressed as upper limits of O(10−8) of the neutrino mixing parameter |Uμ4|2 for N masses in the range 200–384 MeV/c2 and lifetime exceeding 50 ns. The X particle is considered a scalar or vector hidden sector mediator decaying to an invisible final state, and upper limits of the decay branching fraction for X masses in the range 10–370 MeV/c2 are reported for the first time, ranging from O(10−5) to O(10−7). An improved upper limit of 1.0×10−6 is established at 90% CL on the K+→μ+ννν¯ branching fraction.

(Less)
Please use this url to cite or link to this publication:
author
and
author collaboration
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
volume
816
article number
136259
publisher
Elsevier
external identifiers
  • scopus:85104114266
ISSN
0370-2693
DOI
10.1016/j.physletb.2021.136259
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2021 The Author(s)
id
3fc5dbea-638c-45f8-9858-c957af3f0137
date added to LUP
2022-03-30 11:39:40
date last changed
2025-10-14 09:15:53
@article{3fc5dbea-638c-45f8-9858-c957af3f0137,
  abstract     = {{<p>The NA62 experiment at CERN reports searches for K<sup>+</sup>→μ<sup>+</sup>N and K<sup>+</sup>→μ<sup>+</sup>νX decays, where N and X are massive invisible particles, using the 2016–2018 data set. The N particle is assumed to be a heavy neutral lepton, and the results are expressed as upper limits of O(10<sup>−8</sup>) of the neutrino mixing parameter |U<sub>μ4</sub>|<sup>2</sup> for N masses in the range 200–384 MeV/c<sup>2</sup> and lifetime exceeding 50 ns. The X particle is considered a scalar or vector hidden sector mediator decaying to an invisible final state, and upper limits of the decay branching fraction for X masses in the range 10–370 MeV/c<sup>2</sup> are reported for the first time, ranging from O(10<sup>−5</sup>) to O(10<sup>−7</sup>). An improved upper limit of 1.0×10<sup>−6</sup> is established at 90% CL on the K<sup>+</sup>→μ<sup>+</sup>ννν¯ branching fraction.</p>}},
  author       = {{Cortina Gil, E. and Husek, T.}},
  issn         = {{0370-2693}},
  language     = {{eng}},
  month        = {{05}},
  publisher    = {{Elsevier}},
  series       = {{Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics}},
  title        = {{Search for K<sup>+</sup> decays to a muon and invisible particles}},
  url          = {{http://dx.doi.org/10.1016/j.physletb.2021.136259}},
  doi          = {{10.1016/j.physletb.2021.136259}},
  volume       = {{816}},
  year         = {{2021}},
}