Strength of the Σ single-particle potential in nuclei from semiclassical distorted wave model analysis of the (π-, K+) inclusive spectrum

The semiclassical distorted wave model is developed to describe (pi(-), K+) inclusive spectra related to Sigma(-) formation measured at KEK with p(pi) = 1.2 GeV/c. The shape and magnitude of the spectrum obtained with a Si-28 target are satisfactorily reproduced using a repulsive Sigma-nucleus potential whose strength is of the order of 30-50 MeV. This strength is not as large as the value of more than 100 MeV obtained using the estimation presented in the report of the experiment.