Pion production near threshold is investigated in a simple relativistic one-nucleon model, using the pseudoscalar $\pi N$ interaction operator and four-component wave functions both for the projectile and for the description of bound nucleons. Compared to a purely nonrelativistic treatment, based on the Galilean invariant $\pi N$ interaction, the differential cross section in this model exhibits significant differences, even in the most simple approximation.

NUCLEAR REACTIONS Relativistic effects in ($p, \pi$) near threshold.

• Received 5 May 1976

DOI:https://doi.org/10.1103/PhysRevC.15.361