PION FORM FACTORS AT INTERMEDIATE MOMENTUM TRANSFER IN A COVARIANT APPROACH

Abstract

We study the pion electromagnetic and γ*+π⁰→γ transition form factors at intermediate momentum transfer. We calculate soft, nonperturbative corrections to the leading perturbative amplitudes which arise from the component of the pion wave function. We work in Minkowski space and use a Lorentz-covariant, gauge-invariant generalized perturbative integral representation for the amplitudes. For the transition form factor we find relative insensitivity to the detailed nonperturbative structure of the wave function for |q²|≳10 GeV², whereas considerable sensitivity is found for the electromagnetic form factor.