New perturbative calculation of the fermion-boson mass ratio in a supersymmetric quantum field theory

We apply a recently proposed graphical perturbative calculational scheme to a two-dimensional supersymmetric model. Elsewhere, we reported the results of a second-order calculation of the ground-state energy density E in this model with the result that E=0. Here, we calculate the boson-fermion mass ratio R to second order in this new perturbation theory. As in the previous calculation, there is a detailed cancellation between classes of graphs which leads to the unbroken supersymmetric result R=1. .AE