The Quantum Superstring as a WZNW Model with N=2 Superconformal Symmetry

Abstract

We present a new development in our approach to the covariant quantization of superstrings in 10 dimensions which is based on a gauged WZNW model. To incorporate worldsheet diffeomorphisms we need the quartet of ghosts $(b_{zz},c^{z}, \b_{zz}, \g^{z})$ for topological gravity. The currents of this combined system form an N=2 superconformal algebra. The model has vanishing central charge and contains two anticommuting BRST charges, $Q_{S}=Q_{W} + \oint \g^{z} b_{zz} + \oint η_{z}$ and $Q_{V} = \oint c^{z} \Big(T^{W}_{zz} + {1\over 2} T^{top}_{zz}\Big) + \g^{z} (B^{W}_{zz} + {1\over 2} B^{top}_{zz} \Big)$, where $\hat{I}{\cdot }_z$ is obtained by the usual fermionization of $\b_{zz}, \g^{z}$. Physical states form the cohomology of $Q_S+Q_V$, have nonnegative grading, and are annihilated by $b_0$ and ${\hat{I}}_0^2$. We no longer introduce any ghosts by hand, and the formalism is completely Lorentz covariant.

26 pages, harmvac; major additions and new results