Heterotic MSSM on a resolved orbifold

We construct an MSSM with three generations from the heterotic string comed on a smooth 6D internal manifold using Abelian gauge fluxes only. The comcation space is obtained as a resolution of the T 6/Z(2) x Z(2) x Z(2,) free orbifold. The involution of such a resolution breaks the SU(5) GUT group down to the SM gauge using a suitably chosen (freely acting) Wilson line. Surprisingly, the spectrum on a resolution is larger than the one on the corresponding orbifold taking into account and Higgsing due to the blow-up modes. The existence of extra resolution are conected to each other by flop transitions.