Diffusion Cloud-Chamber Study of Very Slow Mesons. II. Beta Decay of the Muon

The spectrum of electrons arising from the decay of the negative mu meson has been determined. The muons are arrested in the gas of a high pressure hydrogen filled diffusion cloud chamber. The momenta of the decay electrons are determined from their curvature in a magnetic field of 7750 gauss. The spectrum of 415 electrons has been analyzed according to the theory of Michel. The shape parameter, {rho}, is found to be 0.64 {plus_minus} .10. The significance of this result in terms of the beta interaction is discussed.