Higher point spin field correlators in D=4 superstring theory

Calculational tools are provided allowing to determine general tree-level scattering amplitudes for processes involving bosons and fermions in heterotic and superstring theories in four space-time dimensions. We compute higher-point superstring correlators involving massless four-dimensional fermionic and spin fields. In D = 4 these correlators boil down to a product of two pure spin field correlators of left- and right-handed spin fields. This observation greatly simplifies the computation of such correlators. The latter are basic ingredients to compute multi-fermion superstring amplitudes in D = 4. Their underlying fermionic structure and the fermionic couplings in the effective action are determined by these correlators. (C) 2010 Elsevier B.V. All rights reserved.