Polarization of recoil protons from proton Compton scattering in the region of the second πN resonance

Abstract

The polarization of recoil protons from proton Compton scattering has been measured at an angle of 90° c.m.s. in the region of the second nucleon resonance. The scattered photons were detected by a telescope which consisted of a lead plate converter, scintillation-counter hodoscopes and a Ćerenkov counter, The angles and momenta of recoil protons were analyzed by a magnet with four spark chambers. The polarization of protons was obtained from the asymmetry in the elastic scattering of protons on carbon in a spark chamber. The polarization of recoil protons from proton Compton scattering are − 0.36 ± 0.29 and − 0.13 ± 0.29 at incident photon energies of 700 ± 50 and 800 ± 50 MeV, respectively. The polarization of recoil protons from neutral pion photoproduction is also obtained and the results are in good agreement with the previous data. A calculation of the polarization of recoil protons in the proton Compton scattering has been made by using an isobar model. The results of the calculation are consistent with the experimental data.