Measurement of the Charged Pion Electromagnetic Form Factor

Abstract

Separated longitudinal and transverse structure functions for the reaction ${}^1\mathrm{H}\left({e,e}^{\prime }{\pi }^{+}\right)n$ were measured in the momentum transfer region $Q^2=0.6\mathrm{}–1.6(\mathrm{GeV}/c{)}^2$ at a value of the invariant mass $W=1.95\mathrm{}\mathrm{GeV}$. New values for the pion charge form factor were extracted from the longitudinal cross section by using a recently developed Regge model. The results indicate that the pion form factor in this region is larger than previously assumed and is consistent with a monopole parametrization fitted to very low $Q^2$ elastic data.