Axial and pseudoscalar nucleon form factors from low energy pion electroproduction

The cross section for exclusive [pi][sup +] electroproduction on the proton has been measured near threshold for the first time at two different values of the virtual photon polarization ([var epsilon][similar to]0.2 and [var epsilon][similar to]0.7). Using the low energy theorem for this reaction we deduce the axial and pseudoscalar weak form factors [ital G][sub [ital A]] and [ital G][sub [ital P]] at [vert bar][ital t][vert bar]=0.073, 0.139, and 0.179 (GeV/[ital c])[sup 2]. The slope of [ital G][sub [ital A]] agrees with the value obtained in neutrino experiments. [ital G][sub [ital P]] satisfies the pion pole dominance hypothesis, which is thus verified for the first time in this range of transfer.