Search for the KL→π0νν¯ decay at the J-PARC KOTO experiment

Abstract

Abstract The KOTO experiment at the J-PARC 30GeV Main Ring aims to study the rare decay K L → π 0 ν ν ¯ . This decay directly breaks the CP symmetry and is highly suppressed in the Standard Model (SM). In addition, the theoretical uncertainties on the decay is only a few percent. Those features make this decay one of the best probes to search for new physics beyond the SM. We had found new background sources from the analysis of the 2016-2018 data set. Thus, we took measures against the new background events. In this paper, we briefly introduce the results of the 2016-2018 data analysis. We thus report the new detectors and analysis tools that we introduced to reduce the new background events and also the other types of background events. Finally, we report the status of the 2021 data analysis.