Relativistic description of exclusive pion production in nucleon-nucleus scattering

Pion-production cross section in p- ¹²C reaction is calculated on the basis of the relativistic impulse approximation (RIA). Nucleon-nucleon elementary amplitude is given in a fully covariant form, and coupling constants and cut-off parameters are determined by fitting elastic nucleon-nucleon scattering at 0.8 GeV. Target wave functions are those of the ground states, which are calculated with the relativistic mean-field theory. Contributions of the distorted waves of produced pion, incoming and outgoing nucleons are evaluated in terms of the optical potential models.