  Although it is not known how to covariantly quantize the Green-Schwarz (GS)
superstring, there exists a semi-light-cone gauge choice in which the GS
superstring can be quantized in a conformally invariant manner. In this paper,
we prove that BRST quantization of the GS superstring in semi-light-cone gauge
is equivalent to BRST quantization using the pure spinor formalism for the
superstring.

High Energy Physics - Theory