Fusion Rules for Affine sl(2|1;C) at Fractional Level k=-1/2

Abstract

We calculate fusion rules for the admissible representations of the affine superalgebra sl(2|1;C) at fractional level k=-1/2 in the Ramond sector. By representing 3-point correlation functions involving a singular vector as the action of differential operators on the sl(2|1;C) invariant 3-point function, we obtain conditions on permitted quantum numbers involved. We find that in this case the primary fields close under fusion.