Measurement of the Charged Pion Electromagnetic Form Factor

Abstract

Separated longitudinal and transverse structure functions for the reaction ${}^{1}\mathrm{H}({e,e}^{\ensuremath{'}}{\ensuremath{\pi}}^{+})n$ were measured in the momentum transfer region ${Q}^{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.6--1.6(\mathrm{GeV}/c{)}^{2}$ at a value of the invariant mass $W\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.95\mathrm{GeV}$. 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.