Measurement of the Michel parameter rho in muon decay
Abstract
The TWIST Collaboration has measured the Michel parameter rho in normal muon
decay,u+ -> e+VeVu. In the standard model of particle physics,rho = 3/4. Deviations
from this value require mixing of left- and right-handed muon and electron couplings in
the muon-decay Lagrangian. We find rho = 0:75080+-0:00032(stat.)+-0:00097(syst.) +- 0:00023, where the last uncertainty represents the dependence of rho on the Michel
parameter n. This result sets new limits on the WL - WR mixing angle in left-right
symmetric models.
Citation
Musser, James Raymond (2005). Measurement of the Michel parameter rho in muon decay. Doctoral dissertation, Texas A&M University. Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /3297.