Dimensionless coupling of superstrings to supersymmetric gauge theories and scale invariant superstring actions

We construct new superstring actions which are distinguished from the standard superstrings by being space-time scale invariant. Like standard superstrings, they are also reparametrization invariant, space-time supersymmetric, and invariant under local scale transformations of the world sheet. We discuss two possible scenarios in which these actions could play a significant role, in particular one which involves their coupling to supersymmetric gauge theories.