Theoretical Study of Pion and Kaon Photoproduction in Nuclei. Final Technical Report

摘要

The contract work was initiated by J. Epstein. The emphasis of the proposal was on (a) the continuation of DWIA calculations of the ( gamma , pi exp +- ) reaction in the delta (1232) region with the extension to the ( gamma , pi exp 0 ) reaction and (b) the application of the DWIA approach to the ( gamma ,K) reaction. The ( gamma , pi exp 0 ) work was intended to be in close collaboration with the experimental studies underway at Bates Linear Accelerator and the ( gamma ,K exp +- ) calculations are relevant to proposed high duty factor electron accelerators in the 1 to 4 GeV region. DWIA calculations were carried out for coherent ( gamma , pi exp 0 ) reactions in sup 12 C. Although the DWIA approach seems less fundamental than the current delta -hole model calculations, we had hopes that it could be more readily applicable to incoherent reactions leaving the target nucleus in the excited state. Epstein hoped to improve the reliability of the DWIA calculations for coherent ( gamma , pi exp 0 ) production by better treatment of the delta propagating in the nuclear medium. In parallel with the ( gamma , pi exp 0 ) work, Epstein carried on an active collaboration with William Donnelly on the ( gamma ,K exp +- ) problem. They had succeeded in a relatively complete description of the reaction for exp 12 C, and were beginning to extend the results to heavy nuclei, when Epstein abruptly resigned his academic post at Boston University (in August 1983) and took an industrial position. Justus Koch of NIKEF, working together with Donnelly, and assisted by modest per diem funds from this grant, the gamma ,K exp +- calculations were carried forward. A copy of the talk by Donnelly entitled Photo- and Electron-Production of Kaons and the Study of Hypernuclei given October 29, 1984 at Bad Honnef, Germany is enclosed. The talk covers the results of the work initiated by Epstein and Donnelly, and completed by Koch and Donnelly. (ERA citation 10:017486)