First Search for the $K_L\to {\pi }^0\gamma$ Decay

Abstract

We report the first search for the $K_L\to {\pi }^0\gamma$ decay, which is forbidden by Lorentz invariance, using the data from 2016 to 2018 at the J-PARC KOTO experiment. With a single event sensitivity of $(7.1\pm 0.3_{stat.}\pm 1.6_{syst.})\times 10^{-8}$, no candidate event was observed in the signal region. The upper limit on the branching fraction was set to be $1.7\times 10^{-7}$ at the 90\% confidence level.

References in corpus (10)

• High-Energy Tests of Lorentz Invariance
• $K^{+}\to {\pi }^{+}\nu \bar{\nu }$ and $K_L\to {\pi }^0\nu \bar{\nu }$ in the Standard Model: Status and Perspectives
• 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
• Testing Local Lorentz and Position Invariance and Variation of Fundamental Constants by searching the Derivative of the Comparison Frequency Between a Cryogenic Sapphire Oscillator and Hydrogen Maser
• K -> pi gamma decays and space-time noncommutativity
• Search for the decay K+ to pi+ gamma gamma in the pi+ momentum region P>213 MeV/c
• New Limit on Lorentz Violation Using a Double-Pass Optical Ring Cavity
• Long-lived neutral-kaon flux measurement for the KOTO experiment
• Development of a low-mass and high-efficiency charged particle detector
• An aerogel Cherenkov detector for multi-GeV photon detection with low sensitivity to neutrons

Cited by in corpus (2)

• Workshop summary -- Kaons@CERN 2023
• New Physics Searches at Kaon and Hyperon Factories