  The theory of a spinor field interacting with a pure Chern-Simons gauge field
in 2+1 dimensions is quantized. Dynamical and nondynamical variables are
separated in a gauge-independent way. After the nondynamical variables are
dropped, this theory reduces to a pure spinor field theory with nonlocal
interaction. Several two-body scattering processes are studied and the cross
sections are obtained in explicitly Lorentz invariant forms.
