Perturbative pion form factor reexamined

We recalculate the pion electromagnetic form factor based on the perturbative QCD formalism that includes the Sudakov resummation. We take into account the evolution of the pion wave function in $b$, which represents the transverse extent of the pion. An infrared enhancement is observed when $1/b$ approaches $\Lambda_{QCD}$. We propose to freeze the evolution of the wave function at some scale above $\Lambda_{QCD}$, such that perturbative contributions are stablized. Our predictions are consistent with experimental data, and insensitive to the variation of relevant parameters.