Pion Form Factors at Intermediate Momentum Transfer in a Covariant Approach

الأصل · EN

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 q q-component of the pion wave function. We work in Minkowski space and use a Lorentz covariant, gauge-invariant generalized perturbative integral representation for the q q amplitudes. For the transition form factor we find relative insensitivity to the detailed nonperturbative structure of the wavefunction for |q²| 10 GeV², whereas considerable sensitivity is found for the electromagnetic form factor.