Electroproduction of single pions at lowεand a measurement of the pion form factor up toQ2=10GeV2

Abstract

We report measurements of the electroproduction of single charged pions from hydrogen and deuterium targets for values of $\ensuremath{\epsilon}$ in the range $0.35<\ensuremath{\epsilon}<0.45$. Data were taken with a hydrogen target at the ($W, {Q}^{2}$) points (2.15 GeV, 1.2 ${\mathrm{GeV}}^{2}$), (2.65, 2.0), (2.65, 3.4), (2.65, 6.0), and (2.65, 10.0). Data were taken with a deuterium target at the ($W, {Q}^{2}$) points (2.15, 1.2) and (2.65, 2.0). The transverse cross section obtained by using these data in conjunction with earlier data at high $\ensuremath{\epsilon}$ to separate the longitudinal and transverse components is used in conjunction with the new data and the $t$-channel Born term to determine the pion form factor and to re-evaluate previously reported measurements. In the range $0.15 \mathrm{Ge}{\mathrm{V}}^{2}<{Q}^{2}<10.0 \mathrm{Ge}{\mathrm{V}}^{2}$ the pion form factor can be described by the simple pole form ${[1+\frac{{Q}^{2}}{(0.462\ifmmode\pm\else\textpm\fi{}0.024)}]}^{\ensuremath{-}1}$.