Measurement of differential cross sections of the $Σ^+p$ elastic scattering in momentum range of 0.44-0.80 GeV/c

Abstract

We performed a novel Σp scattering experiment at the J-PARC hadron experimental facility. Approximately 2400 Σ + p elastic scattering events were identified by requesting the kinematical consistency of the elastic scattering from 4.9 × 10 7 tagged Σ + beam particles in the Σ + momentum range of 0.44 -0.80 GeV/c. The differential cross sections of the Σ + p elastic scattering were derived with much better precision compared to past experiments. The obtained values of differential cross sections are around 2 mb/sr, which are not so large as most theoretical predictions. Moreover, the phase shifts of 3 S 1 and 1 P 1 channels were experimentally derived for the first time. The phase shift of the 3 S 1 channel wherein a large repulsive core was predicted owing to the Pauli effect in the quark level was evaluated to be 20 • < |δ3 S1 | < 35 • . If the sign is assumed to be negative, the strength of the interaction in this channel was found to be moderately repulsive.