Exactly solvable (0,2) supersymmetric string vacua with GUT gauge groups Original Research Article

We present a construction of modular invariant partition functions for heterotic (0, 2) supersymmetric classical string vacua. This generalization of Gepnerʹs construction yields GUT gauge groups E6, SO(10), SU(5) and SU(3) × SU(2) × U(1)r, respectively. By calculating the massless spectrum of some of these models we find strong indications that they correspond to (0, 2) string vacua discussed recently in the context of CYM/LG phases.