Particles, superparticles and twistors

Journal article, 1987

The covariant Green-Schwarz action for a superstring has never been quantized covariantly. The physics behind this is discussed. We then consider the corresponding point-particle action in four dimensions, and write down a master action from which it can be obtained as a gauge choice: the ‘‘space-time gauge.’’ There is also a ‘‘twistor gauge,’’ in which covariant quantization is straightforward (as noted previously by Shirafuji).