THE PHYSICAL PROPAGATOR OF A SLOWLY MOVING CHARGE

We consider an electron which is electromagnetically dressed in such a way that it is both gauge invariant and that it has the associated el ectric and magnetic fields expected of a moving charge, We study the p ropagator of this dressed electron and, for small velocities, show exp licitly at one loop that at the natural (on-shell) renormalisation poi nt, p(0) = m,p = mv, one can renormalise the propagator multiplicative ly. Furthermore the renormalisation constants are infra-red finite. Th is shows that the dressing we use corresponds to a slowly moving, phys ical asymptotic field.