Evaluation of the Inefficiency of a Charged Particle Detector for the KOTO Experiment

Abstract

The rare decay \(K_{L} \to \pi ^{0}\nu \bar{\nu }\) is a good prove for new physics search. The KOTO experiment aims to observe this decay for the first time. To achieve a sensitivity of the Standard Model prediction, a high-efficient charged particle counter is a key component. We designed a charged veto counter which consists of plastic scintillators, wavelength shifting fibers and MPPCs. We evaluated the efficiency of the detector and the detector achieved an efficiency high enough to satisfy the requirements of the KOTO experiment.