Light-cone gauge superstring field theory and dimensional regularization II

We propose a dimensional regularization scheme to deal with the divergences caused by colliding supercurrents inserted at the interaction points, in the light-cone gauge NSR superstring field theory. We formulate the theory in d dimensions and define the amplitudes as analytic functions of d. With an appropriately chosen three-string interaction term and large negative d, the tree level amplitudes for the (NS,NS) closed strings can be recast into a BRST invariant form, using the superconformal field theory proposed in ref. [1]. We show that in the limit d →10 they coincide with the results of the first quantized theory. Therefore we obtain the desired results without adding any contact interaction terms to the action.