Inelastic capture ratio at rest and low-energy cross sections of Sigma(-)pscattering in the SU6 quark model

The inelastic capture ratio at rest, r(R), and low-energy total cross secti ons of Sigma(-)p scattering are examined in the recent SU6 quark model deve loped for a unified description of the NN and YN interactions. The effect o f the small mass difference between Sigma(-)p and Sigma(0)n channels is tre ated approximately and the Coulomb attraction in the Sigma(-)p channel is p roperly incorporated in the particle basis. The model FSS predicts tau(R) = 0.461, which is very close to the experimental value. The low-energy cross sections for the charge exchange reaction Sigma(-)p --> Sigma(0)n are impr oved, although those for Sigma(-)p --> Lambda n are still too large. Predic tions by another model RGM-H are less favorable, even for the very scarce e xperimental data presently available. The effect of the Coulomb force is es timated, and the effective range approximation is examined in the low-energ y S-matrix. The important roles of the one-pion exchange tensor force and t he antisymmetric spin-orbit force in the Sigma N-Lambda N coupling are disc ussed.