A NEW APPROACH TO SUPERSYMMETRY BREAKING IN SUPERSTRING MODELS

We re-examine supersymmetry breaking in effective four-dimensional field theories derived from the superstring, noting three features of modern four-dimensional string theories that were absent in the earlier compactifications of ten-dimensional string theories. These features are: the replacement of gauge-singlet moduli fields by gauge non-singlet chiral supermultiplets, vector-like matter fields in the hidden sector, and extra U(1) gauge symmetries under which both hidden and observable matter fields transform. We point out that an anomalous U(1) gauge symmetry can fix the magnitudes of the ersatz moduli fields. We propose a new scenario in which composite chiral supermultiplets in the hidden sector break global supersymmetry, and the extra massive U(1) gauge supermultiplets communicate this breaking to the observable sector via radiative corrections in the renormalizable effective field theory. © 1990.