  In classical field theory, radiation does not reflect off of reflectionless
kinks. In quantum field theory, radiation quanta, called mesons, can be
reflected. We provide a general analytical formula for the leading order
amplitude and probability for the elastic scattering of mesons off of
reflectionless quantum kinks. In the case of the Sine-Gordon model we verify
that, due to a cancellation of six contributing processes, our general formula
yields an amplitude of zero, as is required by integrability.
