Analysis status of scattering events in the J-PARC E40 experiment

Nanamura, Takuya; Ichikawa, Yudai   ; Hayakawa, Shuhei; Yoshida, Junya; Miwa, Koji*; Honda, Ryotaro*; Akazawa, Yuya*; Yamamoto, Takeshi  

Hyperon-nucleon scattering experiment is one of the powerful methods for studying YN interaction. However, it is difficult due to short lifetime of hyperon. scattering experiments were performed as KEK E251 and KEK E289 in order to measure the differential cross sections. In these experiments, statistics were limited to less than 100 events and differential cross section had too large statistical errors to restrict baryon-baryon interaction models. J-PARC E40 experiment aims for measuring cross sections of scatterings with high statistics (10000 events) by overcoming difficulties of hyperon-nucleon scattering experiment. By using high rate ( 19M /spill) beam and large acceptance spectrometer, we can produce and tag large amount of beam. LH target and surrounding detector system CATCH enable us to reconstruct reactions from two body kinematics. Our experimental group completed data taking and about half of data taking by 2019 Apr. Left data taking will be performed in the end of this fiscal year.