Measurement of the recoil protons in the reaction of γ + p → p + anything for the energy range from 710 to 950 MeV

Abstract

The momentum spectrum of the recoil protons in the reaction γ + p → p + anything is measured in the incident energy range from 710 MeV to 950 MeV. A tagged photon beam is used as an incident photon. From this measurement the cross sections of the reactions, γ + p → p + π + + π − and γ + p → p + π 0 + π 0, are obtained as functions of the energy of the incident photon. The observed ratio of these two reactions ( p + π 0 + π 0) ( p + π + + π −) is about 0.2 in the incident energy region investigated, and is consistent with the excitation of the isospin- 1 2 intermediate state in the s-channel. No serious deviations from the phase space are observed in the missing-mass spectrum of protons.