Radiative Muon Capture and Medium Energy Photon Experiments (Physics)

建议继续在（国际）国家加速器实验室进行中能物理领域的实验。粒子实验在加拿大的TRIUMF加速器上进行。目前正在进行的是测量氢中的辐射μ子捕获。由于分支比例很小，只有亿分之一，所以以前从未进行过这种测量。氢的测量将为半光子弱相互作用的诱导赝标量耦合常数提供一个清晰的测定。核RMC测量数据已完成，目前正在进行分析。他们检查原子核中的重整化效应。该计划的另一部分集中在带有标记的偏振伽马射线束的光核实验上。这些实验是在布鲁克海文国家实验室正在建造的激光电子伽马射线源（LEGS）上开始的。这是一个独特的新设备，其中每个光子以每秒一千万的速度被标记，并且线性和圆形的偏振率大约为90%。第一个实验将通过探测反冲质子来研究氘核的光分解。第二组实验将研究质子和氘核极化光子产生的康普顿散射和中性介子光。反冲质子或中子和光子将在巧合中被探测到。这些测量可以测定核子的电和磁极化率。

A continuation of research at (inter)national accelerator laboratories performing experiments in the area of intermediate energy physics is proposed. Particle experiments are performed at the TRIUMF accelerator in Canada. Presently underway is a measurement of radiative muon capture in hydrogen. This measurement has never before been made due to the small branching ratio, a few parts in one-hundred-million. The hydrogen measurement will provide a clean determination of the induced pseudoscalar coupling constant of the semileptonic weak interaction. The nuclear RMC measurements, data taking completed, are now being analyzed. They check on renormalization effects in nuclei. The other part of the program centers on photonuclear experiments with a tagged polarized gamma ray beam. These experiments have been initiated at the Laser Electron Gamma Ray Source (LEGS) being constructed at Brookhaven National Laboratory. This is a unique new facility in which every photon, at a rate of ten million per second is tagged and polarization of roughly ninety percent both linear and circular is expected. The first experiments will study deuteron photodisintegration by detecting the recoil proton. The second set of experiments will study Compton scattering and neutral pion photoproduction from protons and deuterons with polarized photons. The recoil proton or neutron and photon will be detected in coincidence. These measurements enable the determination of the electric and magnetic polarizabilities of the nucleons.