From January 21st to 23rd, 2026, the 41st J-PARC Program Advisory Committee (PAC) meeting was held at J-PARC. On January 21st, Dr. Gogami presented the preparation status of the "J-PARC E94 Experiment," a project aimed at elucidating "Charge Symmetry Breaking (CSB)" through high-precision spectroscopy of Lambda hypernuclei.

The J-PARC E94 experiment aims to realize measurements under high-intensity beam conditions by introducing a new Acrylic Cherenkov Detector to the high-resolution magnetic spectrometer "S-2S." This upgrade will enable efficient detection of Lambda hypernuclei signals. We reported on the successful prototype test of the detector (Nov. 2025) and various initiatives to improve S-2S momentum analysis:

• Active Sieve Slit: Extracting track patterns through holes to understand S-2S optical properties.
• Advanced Analysis: Magnet model optimization using 3D field calculations and AI-based momentum analysis developed by graduate students.

With "Stage 2" status already granted, we are proceeding with detector development and software refinement, aiming for preparation completion in the summer or autumn of 2026.