Polarization of recoil protons from the photoproduction of neutral pions in hydrogen between 750 and 1450 MeV

[摘要] NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.In a recent experiment on [...] photoproduction at the Caltech 1.5 BeV Electron Synchrotron, the polarization of the recoil proton was measured. The measurement was performed using a scattering and range spark chamber built out of variable thickness carbon modules. The sample of [...] was pure to better than 98%. Approximately 3500 useful scatters were obtained to yield polarization values, around 60[...] c.m. for the produced pion, for incoming photon energies 750 [...] k [...] 1450 MeV.The polarization values were obtained with a maximum likelihood method. A thorough investigation was made of all analyzing power data available for proton carbon scattering.The results indicate a striking angular dependence, with the polarization changing sign for [...] ~ 60[degrees] to 70[degrees] throughout the energy region covered. These results are interpreted in the framework of an isobar model of [...] photoproduction with Regge-ized [...] exchange amplitude added.

[发布机构] University:California Institute of Technology;Department:Physics, Mathematics and Astronomy

[关键词] Physics