Radiative Muon Capture and Medium Energy Photon Experiments (Physics)

辐射μ子捕获和中能光子实验（物理）

• 批准号: 8803425
• 负责人: Marvin Blecher
• 金额: $ 37.28万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-06-01 至 1991-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8803425&HistoricalAwards=false
• 关键词: Radiative; Muon; Capture; Medium; Energy

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.

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研究。粒子实验是在加拿大的TRIUMF加速器进行的。目前正在进行的是对氢气中的辐射缪子俘获的测量。由于分支比很小，以前从未进行过这种测量，只有1亿的几个部分。氢的测量将提供半轻子弱相互作用诱导伪标量耦合常数的干净确定。核RMC测量，数据采集完成，现在正在分析中。他们检查了原子核中的重整化效应。该计划的另一部分集中在使用标记的偏振伽马射线束进行光核实验。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)上启动的。这是一种独特的新设备，在其中以每秒1000万个的速度对每个光子进行标记，预计线偏振和圆偏振都可以达到大约90%。第一个实验将通过探测反冲质子来研究氚的光解。第二组实验将研究康普顿散射和中性介子的光产生，这些介子由带有偏振光子的质子和氚产生。反冲质子或中子和光子将被符合探测到。这些测量能够确定核子的电极化率和磁极化率。