The Analysis Status of Σ⁺p Scattering Events in the J-PARC E40 Experiment

The J-PARC E40 experiment aims for measuring cross sections of the Σp scatterings with high statistics by overcoming difficulties of hyperon-nucleon scattering experiment. The physics motivations are to verify the large repulsive force due to quark Pauli effect in the Σ⁺p interaction and to perform systematic study of the ΣN interaction. Physics data taking was performed at the K1.8 beam line in the J-PARC hadron experimental facility by 2020 June. Σ⁺ particles were produced via the π⁺p→ K⁺Σ⁺ reaction and their momenta were tagged with spectrometers. Recoil proton of the Σ⁺p scatterings and proton from the Σ⁺→ pπ decay were detected with surrounding detector system CATCH. The Σ⁺p scattering can be identified by checking the consistency for the recoil proton between the measured energy and the calculated energy from kinematics of the Σ⁺p scattering. In present analysis, 69M Σ⁺ particles are tagged as the Σ⁺ beam and 4500 Σ⁺p scattering events are identified. Further analysis to derive the differential cross sections is ongoing.