Precision Measurement of the p(e,e′p)π[superscript 0] Reaction at Threshold

New results are reported from a measurement of π[superscript 0] electroproduction near threshold using the p(e,e[superscript ′]p)π[superscript 0] reaction. The experiment was designed to determine precisely the energy dependence of s- and p-wave electromagnetic multipoles as a stringent test of the predictions of chiral perturbation theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the ϕ[* over π] and θ[* over π] angles in the pπ[superscript 0] center of mass was obtained for invariant energies above threshold from 0.5 up to 15 MeV. The 4-momentum transfer Q[superscript 2] coverage ranges from 0.05 to 0.155 (GeV/c)[superscript 2] in fine steps. A simple phenomenological analysis of our data shows strong disagreement with p-wave predictions from ChPT for Q[superscript 2] > 0.07 (GeV/c)[superscript 2], while the s-wave predictions are in reasonable agreement.