Effects of additional Higgses in supersymmetric grand unified theories

We consider modifications of the minimal supersymmetric SU(5) grand unified model. With the additional Higgses 10 +$\text{10}$, the theory may be modified so that the proton decays dominantly via the conventional mode p→e⁺π with the lifetime π_p=(0.04-710)×10³⁰yr, and sin²θ_W=0.222±0.003.