The exclusive electroproduction process $ep\to e^{\prime }{p}^{\prime }{\pi }^0$ was measured in the range of photon virtualities $Q^2=0.4–1.0{\mathrm{GeV}}^2$ and the invariant mass range of the $p{\pi }^0$ system of $W=1.1–1.8$ GeV. These kinematics are covered in exclusive ${\pi }^0$ electroproduction off the proton with nearly complete angular coverage in the $p{\pi }^0$ center-of-mass system and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions ${\sigma }_T+\epsilon {\sigma }_L,{\sigma }_{LT}$, and ${\sigma }_{TT}$, were extracted via fitting the ${\varphi }_{{\pi }^0}$ dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying $N^{*}$ and ${\mathrm{\Delta }}^{*}$ resonances with $M>1.6$ GeV. As part of a broad effort to determine the electrocouplings of the $N^{*}$ and ${\mathrm{\Delta }}^{*}$ resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the $N\pi$ and ${\pi }^{+}{\pi }^{-}p$ channels.

• Received 6 August 2019

DOI:https://doi.org/10.1103/PhysRevC.101.015208