Chiral supersymmetric Standard Model spectra from orientifolds of Gepner models

We construct d = 4, N = 1 orientifolds of Gepner models with just the chiral spectrum of the Standard Model. We consider all simple current modular invariants of c = 9 tensor products of N = 2 minimal models. For some very specific tensor combinations, and very specific modular invariants and orientifold projections, we find a large number of such spectra. We allow for Standard Model singlet (dark) matter and non-chiral exotics. The Chan-Paton gauge group is either U(3) x Sp(2) x U(1) x U(1) or U (3) x U (2) x U (1) x U (1). In many cases the Standard Model hypercharge U (1) has no coupling to RR 2-forms and hence remains massless; in some of those models the B-L gauge boson does acquire a mass. (c) 2005 Elsevier B.V. All rights reserved.