The perturbative pion form factor with Sudakov suppression

We give a modified perturbative expression for the pion electromagnetic form factor in perturbative QCD, which includes Sudakov suppression of the elastic scattering of quarks that are isolated in space. Beyond momentum transfers of 20Λ _QCD the perturbative calculation becomes relatively insensitive to soft gluon exchange. Our analysis involves no phenomenological parameters such as a gluon mass, and may be applied to the proton form factor.