Measurement of the Electron Spectrum from Muon Decay, and Its Implications
Measurement of the Electron Spectrum from Muon Decay, and Its Implications
复制标题
μ 子衰变电子能谱的测量及其意义
DOI：
10.1103/physrevlett.16.540
复制
发表时间：
1966
期刊：
影响因子：
--
通讯作者：
J. Bounin
中科院分区：
文献类型：
--
作者：
R. Ehrlich;D. Fryberger;R. Powers;B. Sherwood;V. Telegdi;J. Bounin
这封信有两个目的：（a）描述用一种新技术对所讨论的光谱进行精确测量，包括确定r）;（B）讨论关于VA理论的有效性的解释，以及类似的实验。e测量衰变正电子在均匀场中的动量，用七个带磁芯读数的火花室（四个用于半径测量，三个用于螺距测量）描绘出它们的螺旋轨迹，火花室放置在磁体中，如图1（a）所示。这种非聚焦谱仪的一些显著特点是：（1）避免了壁面和狭缝散射;（2）在固定的均匀场上具有大的动量接受能力（aP= 30%）;（3）在AP内具有几乎与动量无关的立体角;（4）良好的动量分辨能力（dp/P= 1%）;（5）对~-p.（6）对极化μ子正电子能谱测量的适应性强[（4）有明显变化]。特征（1）和（2）是相对于在该领域中使用的经典光谱仪的改进，但是被哥伦比亚的声波火花室装置共享。
This Letter has two goals:(a) to describe an accurate measurement, by a novel technique, 4 of the spectrum in question, including a deter-mination of r),(b) to'discuss the interpretation, as regards the validity of the VA theory, of this and kindred experiments.% e measure the momenta of the decay positrons in a homogeneous field, delineating their helical trajectories by means of seven wire spark chambers with magnetic core readout (four for radius and three for pitch determina-tion), placed within a magnet as shown in Fig. 1 (a). The following are some of the salient features of this nonfocusing spectrometer:(1) avoidance of wall and slit scattering;(2) large momen-tum acceptance (aP= 30%) at a fixed, homogeneous field;(3) virtually momentum-inde-pendent solid anglewithin AP;(4) fair momen-tum resolution (dp/P= 1%);(5) positive identification of the~-p.-e decay chain in the source;(6) ready adaptability to the measurement of the positron spectrum for polarized muons [with obvious changes in (4)]. Features (1) and (2) are improvements with respect to the classical spectrometers used in this field, but are shared by Columbia's sonic spark chamber apparatus.