Jul 6 – 13, 2022
Bologna, Italy
Europe/Rome timezone

Status of the KL->pi0 nu number study at the J-PARC KOTO experiment

Jul 7, 2022, 5:51 PM
Room 9 (Indaco)

Room 9 (Indaco)

Parallel Talk Quark and Lepton Flavour Physics Quark and Lepton Flavour Physics


Yu-Chen Tung (National Taiwan University)


The KOTO experiment studies the CP-violating rare decay $K_L \to \pi^0 \nu \overline{\nu}$, conducting with the 30-GeV Main Ring Proton Synchrotron at J-PARC in Japan. In the previous analysis on data taken in 2016-18, we found three candidate events in the signal region with a single event sensitivity of $7\times 10^{-10}$, which is statistically consistent with the background expectation. The dominant background source then was the charged kaon contamination in the neutral beam.
Since 2020, we have accumulated data with a new detector that detects the charged kaon in the beam to suppress such backgrounds. We are analyzing data, taken in 2021 in particular, whose statistics corresponds to a similar sensitivity. We will report the status of the analysis and plans for the next run.

In-person participation No

Primary authors

Tadashi Nomura (KEK/J-PARC) Yu-Chen Tung (National Taiwan University)

Presentation materials