Electromagnetic and weak masses

In theories with spontaneously broken gauge symmetries, various masses, or mass differences may vanish in zeroth order as a consequence of the representation content of the fields appearing in the Lagrangian. These masses or mass differences can then be calculated as finite higher-order effects. The mechanism for cancelation of divergences in second-order fermion masses is described explicitly. The weak interactions play an essential role in canceling infinities in electromagnetic masses.