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Search for π0 decays to invisible particles

Cortina Gil, E. and Husek, T. LU (2021) In Journal of High Energy Physics 2021(2).
Abstract

The NA62 experiment at the CERN SPS reports a study of a sample of 4 × 109 tagged π0 mesons from K+ → π+π0(γ), searching for the decay of the π0 to invisible particles. No signal is observed in excess of the expected background fluctuations. An upper limit of 4.4 × 10−9 is set on the branching ratio at 90% confidence level, improving on previous results by a factor of 60. This result can also be interpreted as a model- independent upper limit on the branching ratio for the decay K+ → π+X, where X is a particle escaping detection with mass in the range 0.110–0.155 GeV/c2 and rest lifetime greater than 100 ps. Model-dependent... (More)

The NA62 experiment at the CERN SPS reports a study of a sample of 4 × 109 tagged π0 mesons from K+ → π+π0(γ), searching for the decay of the π0 to invisible particles. No signal is observed in excess of the expected background fluctuations. An upper limit of 4.4 × 10−9 is set on the branching ratio at 90% confidence level, improving on previous results by a factor of 60. This result can also be interpreted as a model- independent upper limit on the branching ratio for the decay K+ → π+X, where X is a particle escaping detection with mass in the range 0.110–0.155 GeV/c2 and rest lifetime greater than 100 ps. Model-dependent upper limits are obtained assuming X to be an axion-like particle with dominant fermion couplings or a dark scalar mixing with the Standard Model Higgs boson.

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type
Contribution to journal
publication status
published
subject
keywords
Beyond Standard Model, Exotics, Fixed target experiments, Rare decay
in
Journal of High Energy Physics
volume
2021
issue
2
article number
201
publisher
Springer
external identifiers
  • scopus:85101791870
ISSN
1029-8479
DOI
10.1007/JHEP02(2021)201
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2021, The Author(s).
id
79994cf9-0029-4e17-bccf-83fd34634f90
date added to LUP
2022-03-30 11:42:47
date last changed
2024-04-12 02:21:59
@article{79994cf9-0029-4e17-bccf-83fd34634f90,
  abstract     = {{<p>The NA62 experiment at the CERN SPS reports a study of a sample of 4 × 10<sup>9</sup> tagged π<sup>0</sup> mesons from K<sup>+</sup> → π<sup>+</sup>π<sup>0</sup>(γ), searching for the decay of the π<sup>0</sup> to invisible particles. No signal is observed in excess of the expected background fluctuations. An upper limit of 4.4 × 10<sup>−9</sup> is set on the branching ratio at 90% confidence level, improving on previous results by a factor of 60. This result can also be interpreted as a model- independent upper limit on the branching ratio for the decay K<sup>+</sup> → π<sup>+</sup>X, where X is a particle escaping detection with mass in the range 0.110–0.155 GeV/c<sup>2</sup> and rest lifetime greater than 100 ps. Model-dependent upper limits are obtained assuming X to be an axion-like particle with dominant fermion couplings or a dark scalar mixing with the Standard Model Higgs boson.</p>}},
  author       = {{Cortina Gil, E. and Husek, T.}},
  issn         = {{1029-8479}},
  keywords     = {{Beyond Standard Model; Exotics; Fixed target experiments; Rare decay}},
  language     = {{eng}},
  number       = {{2}},
  publisher    = {{Springer}},
  series       = {{Journal of High Energy Physics}},
  title        = {{Search for π<sup>0</sup> decays to invisible particles}},
  url          = {{http://dx.doi.org/10.1007/JHEP02(2021)201}},
  doi          = {{10.1007/JHEP02(2021)201}},
  volume       = {{2021}},
  year         = {{2021}},
}