The Recoil Proton Polarization in π⁻ Photoproduction From Deuterium Between 450 and 950 MeV and a Partial Wave Analysis of γn → π⁻ p in the Resonance Region

Citation

Metcalf, William James (1974) The Recoil Proton Polarization in π⁻ Photoproduction From Deuterium Between 450 and 950 MeV and a Partial Wave Analysis of γn → π⁻ p in the Resonance Region. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/06Y0-2Z64. https://resolver.caltech.edu/CaltechETD:etd-05022005-103327

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. In an experiment performed at the Caltech synchrotron the recoil proton polarization in the reaction [...] has been measured at CM pion angles of 90[degrees] and 120[degrees] in the region from 450 to 900 MeV in lab photon energy. A deuterium target was used and the observed reaction [...] was related to [...] by a simple spectator model. The polarization was determined from the distribution in the azimuthal scattering angle, [...], of the recoil protons from carbon in a range-scattering chamber consisting of alternate spark gaps and carbon plates. A maximum likelihood method was used to extract the polarization from the observed [...] distribution of the p-C scatters. The [...] coincident with the recoil proton was detected in a magnetic spectrometer where its momentum was quite accurately determined. Background contamination was less than 2% and the inelasticity of the p-C scatters was included in the calculation of the carbon analyzing power. However, the uncertainty in this inelasticity was the primary source of systematic error. The resulting polarizations were fit, along with other data on the reaction [...], using a resonance-background model of pion photoproduction in order to determine the couplings of many I = 1/2 nucleon isobars to this reaction. These couplings, several of which are better determined than in previous studies, are compared to quark model predictions. The quark model is found to give a very good description of many of these couplings.

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