Muon Decay Asymmetry

Angular distribution of the e+ from µ+ decay: the asymmetry (anisotropy) of the distribution is 100% for the highest e+ energy (52.83 MeV) and zero (i.e., an isotropic distribution) for half as big an e+ energy. For zero e+ energy (not shown) the asymmetry is negative.

Solid lines: energy spectrum E(x)/2 (e+ energy = x times 52.83 MeV) from normal µ+ decay and x-dependence of µ+ decay asymmetry a(x) [degree of correlation between e+ momentum and µ+ spin direction]. Dashed line: weighted µ+ decay asymmetry spectrum, the product of E(x)/2 and a(x).
Jess H. Brewer
Last modified: Fri Nov 28 17:53:24 EST