K. Shiomi

activity

20142026

K_{L} \to π^{0} ν ν

and

K_{L} \to π^{0} X^{0}

Decays at the J-PARC KOTO Experiment

176 citations · 358 across the 20 of their papers we have counts for

collaborators

20 papers

hep-ex2026

The Search for $K_{L} \to π^{0} π^{0} γ γ$ and $K_{L} \to π^{0} π^{0} X$ where $X \to 2 γ$ at the KOTO Experiment

J. Redeker, C. Lin, Y. W. Wah +23

We performed searches for $K_{L} \to π^{0} π^{0} X$ where $X$ may be an axion-like particle which promptly decays to two photons, and the first search for $K_{L} \to π^{0} π^{0} γ γ$ …

hep-ex2025

Search for Dark Particles in $K_{L}^{0} \to γ X$ at the KOTO Experiment

T. Wu, Y. C. Tung, Y. B. Hsiung +24

We report a search for an invisible particle $X$ in the decay $K_{L}^{0} \to γ X$ ( $X \to invisible$ ), where $X$ can be interpreted as a massless or massive dark photon. N…

hep-ex2025

Experimental Study of Rare Kaon Decays at J-PARC with KOTO and KOTO II

J. K. Ahn, E. Augustine, L. Bandiera +62

The rare kaon decay $K_{L} \to π^{0} ν ν ˉ$ is extremely sensitive to new physics, because the contribution to this decay in the Standard Model (SM) is highly suppressed and known very a…

hep-ph2025

Kaon Physics: A Cornerstone for Future Discoveries

Jason Aebischer, Atakan Tugberk Akmete, Riccardo Aliberti +153

The kaon physics programme, long heralded as a cutting-edge frontier by the European Strategy for Particle Physics, continues to stand at the intersection of discovery and innovati…

hep-ex2025★ 1 cited

Proposal of the KOTO II experiment

Jung Keun Ahn, Antonella Antonelli, Giuseppina Anzivino +79

The KOTO II experiment is proposed to measure the branching ratio of the decay $K_{L} \to π^{0} ν ν ˉ$ at J-PARC. With a beamline to extract long-lived neutral kaons at 5 degrees from a…

hep-ex2024★ 19 cited

Search for the $K_{L} \to π^{0} ν ν ˉ$ Decay at the J-PARC KOTO Experiment

KOTO Collaboration, J. K. Ahn, M. Farriagton +47

We performed a search for the $K_{L} \to π^{0} ν ν ˉ$ decay using the data taken in 2021 at the J-PARC KOTO experiment. With newly installed counters and new analysis method, the ex…

physics.ins-det2024★ 1 cited

Measurement of muon flux behind the beam dump of the J-PARC Hadron Experimental Facility

T. Matsumura, Y. Hirayama, G. Y. Lim +4

A muon-flux measurement behind the beam dump of the J-PARC Hadron Experimental Facility was performed with a compact muon detector that can be inserted into a vertical observing ho…

hep-ph2023★ 4 cited

Workshop summary -- Kaons@CERN 2023

G. Anzivino, S. Arguedas Cuendis, V. Bernard +60

Kaon physics is at a turning point -- while the rare-kaon experiments NA62 and KOTO are in full swing, the end of their lifetime is approaching and the future experimental landscap…

hep-ex2023

Suppression of Neutron Background using Deep Neural Network and Fourier Frequency Analysis at the KOTO Experiment

Y. -C. Tung, J. Li, Y. B. Hsiung +9

We present two analysis techniques for distinguishing background events induced by neutrons from photon signal events in the search for the rare $K_{L}^{0} \to π^{0} ν ν ˉ$ decay a…

hep-ex2022★ 3 cited

Search for the Pair Production of Dark Particles $X$ with $K_{L}^{0} \to X X$ , $X \to γ γ$

C. Lin, J. K. Ahn, J. M. Choi +39

We present the first search for the pair production of dark particles $X$ via $K_{L}^{0} \to X X$ with $X$ decaying into two photons using the data collected by the KOTO experiment. No s…

nucl-ex2021★ 22 cited

Extension of the J-PARC Hadron Experimental Facility: Third White Paper

Kazuya Aoki, Hiroyuki Fujioka, Toshiyuki Gogami +40

The J-PARC Hadron Experimental Facility was constructed with an aim to explore the origin and evolution of matter in the universe through the experiments with intense particle beam…

hep-ex2020★ 57 cited

Study of the $K_{L} \to π^{0} ν ν$ Decay at the J-PARC KOTO Experiment

KOTO Collaboration, J. K. Ahn, B. Beckford +68

The rare decay $K_{L} \to π^{0} ν ν$ was studied with the dataset taken at the J-PARC KOTO experiment in 2016, 2017, and 2018. With a single event sensitivity of $( 7.20 \p…

hep-ex2020★ 3 cited

First Search for the $K_{L} \to π^{0} γ$ Decay

J. K. Ahn, B. Beckford, M. Campbell +59

We report the first search for the $K_{L} \to π^{0} γ$ decay, which is forbidden by Lorentz invariance, using the data from 2016 to 2018 at the J-PARC KOTO experiment. With a single ev…

hep-ex2018★ 176 cited

Search for $K_{L} \to π^{0} ν ν$ and $K_{L} \to π^{0} X^{0}$ Decays at the J-PARC KOTO Experiment

KOTO Collaboration, J. K. Ahn, B. Beckford +67

A search for the rare decay $K_{L} \to π^{0} ν ν$ was performed. With the data collected in 2015, corresponding to $2.2 \times 1 0^{19}$ protons on target, a single event se…

hep-ex2016★ 20 cited

A new search for the $K_{L} \to π^{0} ν ν$ and $K_{L} \to π^{0} X^{0}$ decays

J. K. Ahn, K. Y. Baek, S. Banno +87

We searched for the $C P$ -violating rare decay of neutral kaon, $K_{L} \to π^{0} ν ν$ , in data from the first 100 hours of physics running in 2013 of the J-PARC KOTO experimen…

physics.ins-det2015★ 13 cited

Development of a low-mass and high-efficiency charged particle detector

D. Naito, Y. Maeda, N. Kawasaki +8

We developed a low-mass and high-efficiency charged particle detector for an experimental study of the rare decay $K_{L} \to π^{0} ν ν ˉ$ . The detector is important to suppres…

physics.ins-det2015★ 14 cited

Long-lived neutral-kaon flux measurement for the KOTO experiment

T. Masuda, J. K. Ahn, S. Banno +54

The KOTO ( $K^{0}$ at Tokai) experiment aims to observe the CP-violating rare decay $K_{L} \to π^{0} ν ν ˉ$ by using a long-lived neutral-kaon beam produced by the 30 GeV proton…

physics.ins-det2014★ 11 cited

An aerogel Cherenkov detector for multi-GeV photon detection with low sensitivity to neutrons

Y. Maeda, N. Kawasaki, T. Masuda +10

We describe a novel photon detector which operates under an intense flux of neutrons. It is composed of lead-aerogel sandwich counter modules. Its salient features are high photon…

hep-ex2014★ 8 cited

$K_{L}^{0} \to π^{0} ν ν ˉ$ at KOTO

Koji Shiomi

The KOTO experiment aims to discover the rare decay $K_{L}^{0} \to π^{0} ν ν ˉ$ at J-PARC. This mode breaks the CP symmetry directly and is highly suppressed in the Standar…

physics.ins-det2014★ 6 cited

Photon-Veto Counters at the Outer Edge of the Endcap Calorimeter for the KOTO Experiment

T. Matsumura, T. Shinkawa, H. Yokota +17

The Outer-Edge Veto (OEV) counter subsystem for extra-photon detection from the backgrounds for the? $K_{L}^{0} \to π^{0} ν ν ˉ$ decay is located at the outer edge of the endcap Cs…

The Search for KL​→π0π0γγ and KL​→π0π0X where X→2γ at the KOTO Experiment

Search for Dark Particles in KL0​→γX at the KOTO Experiment