A new search for the $K_L\to {\pi }^0\nu \overline{\nu }$ and $K_L\to {\pi }^0{X}^0$ decays

Abstract

We searched for the $CP$-violating rare decay of neutral kaon, $K_L\to {\pi }^0\nu \overline{\nu }$, in data from the first 100 hours of physics running in 2013 of the J-PARC KOTO experiment. One candidate event was observed while $0.34\pm 0.16$ background events were expected. We set an upper limit of $5.1\times 10^{-8}$ for the branching fraction at the 90\% confidence level (C.L.). An upper limit of $3.7\times 10^{-8}$ at the 90\% C.L. for the $K_L\to {\pi }^0{X}^0$decay was also set for the first time, where $X^0$ is an invisible particle with a mass of 135 MeV/$c^2$.

arXiv comment11 pages, 5 figures, to be published in PTEP

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Cited by in corpus (12)

• Search for $K_L\to {\pi }^0\nu \overline{\nu }$ and $K_L\to {\pi }^0{X}^0$ Decays at the J-PARC KOTO Experiment
• Exploratory Lattice QCD Study of the Rare Kaon Decay $K^{+}\to {\pi }^{+}\nu \bar{\nu }$
• $R_{K^{(\ast )}}$ and related $b\to s\ell \bar{\ell }$ anomalies in minimal flavor violation framework with $Z^{\prime }$ boson
• Footprints of leptoquarks: from $R_{K^{(\ast )}}$ to $K\to \pi \nu \bar{\nu }$
• Lattice QCD study of the rare kaon decay $K^{+}\to {\pi }^{+}\nu \bar{\nu }$ at a near-physical pion mass
• Sterile neutrinos facing kaon physics experiments
• Pair production of dark particles in meson decays
• Flavor from the double tetrahedral group without supersymmetry: flavorful axions and neutrinos
• Flavor-changing axions and Dirac neutrino masses
• Prospects for an experiment to measure BR($K_L\to {\pi }^0\nu \bar{\nu }$) at the CERN SPS
• Summary of the CKM 2016 working group on rare decays
• Pionium as a source of false events in the $K\to \pi \nu \bar{\nu }$ decays