A heterotic N=2 string with space-time supersymmetry

We reconsider the issue of embedding space-time fermions into the four-dimensional N = 2 worldsheet supersymmetric string. A new heterotic theory is constructed, taking the right-movers from the N = 4 topological extension of the conventional N = 2 string but a c = 0 conformal field theory supporting target-space supersymmetry for the left-moving sector. The global bosonic symmetry of the full formalism proves to be U (1, 1), just as in the usual N = 2 string. Quantization reveals a spectrum of only two physical states, one boson and one fermion, which fall in a multiplet of (1, 0) supersymmetry. (C) 2001 Elsevier Science B.V. All rights reserved.