Abstract
The Michel Parameter ρ is one of the parameters in the theoretical expression for the differential decay rate of polarized muons. In the fall of 1993, the MEGA collaboration conducted an experiment to obtain a more precise determination of ρ. The experiment was carried out with the existing MEGA positron spectrometer, which consists of plastic scintillators forming two hollow barrels, and 8 cylindrically shaped multi-wire proportional chambers arranged such that seven smaller ones surround a larger central one. In this experiment the energies of decay positrons were measured. ρ can be extracted from the energy spectrum by fitting it to that of Monte Carlo simulations. The uncertainty of the ρ measurement is limited by the systematic errors. A precision of δρ = 0.001 is intended to be achieved, which is a factor of 3 better than the current best value, ρ = 0.7518 [plus or minus] 0.0026. This dissertation reports the preliminary results of the data analysis, where ρ = 0.7488 [plus or minus] 0.0045(sta)[plus or minus] 0.0024(sys) is obtained.
Liu, Fan (1994). Measurement of the Michel Parameter p with the MEGA positron spectrometer. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1554997.