CONTINUUM CONTRIBUTIONS TO PION RADIUS

We calculate continuum contributions to the mean-square radius of the pion. The calculation is based on the assumption of vector dominance of the hadronic electromagnetic current. Vector dominance is introduced through the use of field-current identities which relate the form factor to the form factor. Then we assume dispersion and elastic unitarity equations in order to determine the form factor. In particular, the interaction used in the elastic unitarity equation is assumed to consist of t-channel exchange of a meson. We also consider the case where the interaction consists of t-channel exchange of a scalar meson. In both cases, continuum contributions to the pion radius were found to be small compared to the pole contribution. © 1969 The American Physical Society.