The S-matrix operator for relativistic theory of charged scalar partic
les interacting via Chern-Simons field is constructed and is shown to
be formally the same as the S-matrix in relativistic scalar quantum el
ectrodynamics in which the Feynman diagrams with external photon lines
are not considered and the propagators of the Chern-Simons particles
are substituted in place of the ones for photons. All the one-loop Fey
nman diagrams for relativistic scattering amplitude of two charged par
ticles are calculated. Due to the renormalizability of the theory only
two diagrams have linear divergence, which are regularized. The nonre
lativistic limit of the scattering amplitude is also finite, unlike th
e non-relativistic Chern-Simons scattering theory. It is found that fo
r a certain value of the contact interaction, corresponding to the rep
ulsive case, the scattering amplitude coincides with that of Aharonov-
Bohm scattering, in the same approximation. (C) 1996 Academic Press, I
nc.