Hard-soft renormalization of the massless Wess-Zumino model 1 Work supported in part by M.U.R.S.T. a

Abstract We show that in a Wilsonian renormalization scheme with zero-momentum subtraction point the massless Wess-Zumino model satisfies the non-renormalization theorem; the finite renormalization of the superpotential appearing in the usual non-zero momentum subtraction schemes is thus avoided. We give an exact expression of the beta and gamma functions in terms of the Wilsonian effective action; we prove the expected relation β =3 gγ . We compute the beta function at the first two loops, finding agreement with previous results.