Recoil-Proton Polarization in Neutral-Pion Photoproduction and in Proton Compton Scattering

Abstract

We have measured the polarization of the recoil proton in the reactions $\gamma p\to {\pi }^{0}p$ and $\gamma p\to \gamma p$ for incident photon energies between 3 and 7 GeV, and $t$ values from -0.2 to -0.65 Ge${\mathrm{V}}^2$. The polarization in neutral-pion production varies from 0 to -1 over this range. Contrary to expectation, it does not agree completely with the polarized-target asymmetry.