On February 2-3, 2026, the Master's Thesis Presentation for the Department of Physics II, Kyoto University was held. From our Strangeness Nuclear Physics Group, Mr. Taniguchi (M2) presented his research titled: "Development of Acrylic Cherenkov Detector for High-Precision Spectroscopy of Λ Hypernuclei using S-2S."

This research supports the J-PARC E94 Experiment, which aims to produce Lambda hypernuclei using high-intensity beams at J-PARC and precisely measure their mass. This study deepens our understanding of the "strong interaction" and provides microscopic insights into the internal structure of neutron stars, complementing macroscopic observations from gravitational waves and X-ray pulsars.

The E94 experiment specifically targets the observation of "Charge Symmetry Breaking (CSB)" in Lambda-nucleon interactions. By comparing our data with mirror nuclei results from our group's project at JLab (USA), we aim to solve the mystery of CSB origin.

Mr. Taniguchi led the development of the "UV-Transparent Acrylic Cherenkov Detector (UC)" to improve the signal-to-noise ratio under high-intensity beam conditions. Through prototyping and beam testing with antiprotons and pions, he successfully identified a detector configuration that meets the requirements. We plan to complete the construction of the actual detector by this summer or autumn.