Taku Yamanaka

Measurement of positron lifetime to probe the mixed molecular states of liquid water

Positron lifetime spectra were measured in liquid water at temperatures between 0 °C and 50 °C. The long lifetime of ortho-positronium atoms (o-Ps) determined by electron pick-off in molecular substances decreases smoothly by 10% as the temperature is raised. This lifetime temperature dependence can be explained by combining the Ps-bubble model and the mixture state model of liquid water.

Development of a Neutral Beam Profile Monitor

We developed a novel beam profile monitor for measuring the shape of an intense neutral beam for particle physics. This monitor is based on a detector technology of scintillating fibers, photomultiplier tubes, and sampling ADCs. It has an advantage for its simplicity, reliability, flexibility, and versatility. This monitor was installed in the small-diameter neutral beam for the KL0 →π0 νν experiment at J-PARC. We report in this article the development and performance of this monitor.

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

The KOTO (

The data acquisition system for the KOTO experiment

K^0

Testing the CKM Model with Kaon Experiments

at Tokai) experiment aims to observe the CP-violating rare decay

P erformance of KOTO CsI Calorimeter

K_L \rightarrow \pi^0 \nu \bar{\nu}

Pulse Identification Method for Overlapped Pulses

by using a long-lived neutral-kaon beam produced by the 30 GeV proton beam at the Japan Proton Accelerator Research Complex. The

Rare Kaon and Pion Decays: Incisive Probes for New Physics Beyond the Standard Model

K_L

The J-PARC KOTO experiment

flux is an essential parameter for the measurement of the branching fraction. Three

A new search for the KL → π0ν ν and KL → π 0X0 decays

K_L