Charge-exchange and helicity-flip scattering in the field of a 't Hooft-Polyakov monopole

An isodoublet of fermions with unequal masses in the field of a 't Hooft-Polyakov monopole is considered. Charge-exchange and helicity-flip cross sections are derived for J = 0 in the limit (E/sub f/,m/sub f/)/M/sub GUT/..-->..0 and e/sup 2/..-->..0. The relevance of our results for the Rubakov-Callan effect is discussed.