  We discuss the scattering of relativistic spin zero particles by an
infinitely long and arbitrarily thin solenoid. The exact solution of the
first-quantized problem can be obtained as a mimic of the nonrelativistic case,
either in the original Aharonov-Bohm way or by using the Berry's magnetization
scheme. The perturbative treatment is developed in the Feshbach-Villars
two-component formalism for the Klein-Gordon equation and it is shown that it
also requires renormalization as in the Schrodinger counterpart. The results
are compared with those of the field theoretical approach which corresponds to
the two-body sector of the scalar Chern-Simons theory.
