Difficulty in determining the pion form factor at high Q^{2}

Abstract

We reexamine the determination of the pion form factor at large spacelike ${\mathit{Q}}^2$ via the reaction ep→en${\mathrm{\pi }}^{+}$ and find that, because of the magnitude of the pion-nucleon form factor and the existence of competing hitherto uncalculated processes in QCD, the pion electromagnetic form factor is not sufficiently well determined at higher ${\mathit{Q}}^2$ to compare with the expected scaling prediction of QCD. Instead, we conclude that the best way to get information about the pion electromagnetic form factor is to study ${\mathrm{\pi }}^0$ production.