Minimal SUSY SU(5) with extra vectorlike matter

It is shown that the minimal renormalizable supersymmetric SU(5) grand unified theory can be made realistic by the inclusion of a single vectorlike 5 + 5 pair. Such a modification can at the same time correct the usual bad mass relations for the first two generations and safely increase the nucleon lifetime. The model predicts the lifetime of at least some decay rate to be less than approximately 1034 yrs, provided that all the superpartners of the minimal supersymmetric standard model lie below 3 TeV. The two statements will be tested by the next proton decay measurements and LHC, respectively.