The cross section for photoproduction of single ${\pi }^{+}$ from hydrogen has been measured at laboratory angles of 110°, 127.5° and 152°, between 0.9- and 3.2-GeV incident photon energy. Measurements have been made with approximately 15% statistical accuracy at about 40 photon energies at each angle. The results agree well with the previous Caltech data of Thiessen. The cross section shows a rapid drop with increasing energy with superimposed bumps or shoulders corresponding to the $N\left(1688\right)\mathrm{}$, $\Delta \mathrm{}\left(1920\right)\mathrm{}$, and $\Delta \mathrm{}\left(2420\right)\mathrm{}$. A shallow minimum is observed at the $N\left(2190\right)\mathrm{}$ resonance.

• Received 10 November 1969

DOI:https://doi.org/10.1103/PhysRevD.1.1946