Electron Decay Branching Ratio of the Pion

Download or read book Electron Decay Branching Ratio of the Pion written by Alan Strelzoff and published by . This book was released on 1964 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ratio of the pion decay rates for the processes, pi yields e + nu and pi yields mu + nu was measured. A large NaI (tl) crystal was used to separate the high energy pion decay electrons from the continuous spectrum of the pi-mu-e chain. Counting decay electrons immediately following a pion stop, the ratio by a direct comparison of pi-e and pi-mu-e electrons was determined. From an observed 10,891 pi-e electrons a precision of 1.8% was attained in the guantity (pion lifetime x branching ratio). Considering the present uncertainty in the pion lifetime the branching ratio, (1.247 = 0.028) x 10 to the -4 power is obtained. This is in good agreement with the theoretical value, 1.233 x 10 to the -4 power, required by the V-A theory when radiative corrections are included. (Author).