Partial Wave Analysis of the Experimental Photomeson Cross Sections

The experimental data concerning photopion production is studied for photon energies below 400 Mev. The data are analyzed in terms of $S$- and $P$-waves of the final pion-nucleon system, and an indication is obtained of the importance of higher partial waves. The "(3,3) state" matrix elements seem to be significantly larger than the other $P$-wave matrix elements at energies below 400 Mev, but not at higher energies. The energy dependence of the various partial waves can be understood on the basis of rather general arguments.