Photoproduction ofπ0Mesons in Hydrogen

Abstract

This paper reports measurements of the total cross section from 150 to 240 Mev of incident photon energy and measurements of the 135° differential cross section from 180 to 215 Mev. A Monte Carlo evaluation of the $\gamma$-ray telescope efficiency by means of an electronic digital computer is outlined. The combined results indicate that a small but finite amount of $S$-state production occurs and that the angular distribution becomes flatter as the energy decreases. The latter effect is associated with production in unenhanced $P$-states and with a lack of electric quadrupole production. Good agreement with the Chew-Low theory is demonstrated by a comparison between the photoproduction and scattering of ${\pi }^0$-mesons, where the scattering cross sections are derived from those for charged mesons by charge independence.