Proton pole contribution in proton decay

We show that nucleon pole terms contribute significantly to proton decay, increasing the branching ratio for e⁺π⁰ and $\text{ν}{}_{\mathrm{<mtext>R</mtext>}}\text{π}{}^{\mathrm{+}}$ modes. The total lifetime is decreased to the point where keeping the SU(5) value of the lifetime below the experimental upper bound forces us to the choice of QCD scale parameter and proton radius parameter which are near the edge of the allowed region.