Measurement of the Michel Parameters {rho} with the MEGA positron spectrometer

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Bulletin of the American Physical Society

OSTI ID:243715

Liu, F

{rho} is one of the Michel Parameters in the theoretical expression for the differential decay rate of polarized muons. The MEGA collaboration has recently conducted an experiment that should improve the precision of {rho} by at least a factor of 2 from its current best value, {rho} = 0.7518 {+-} 0.0026. In this experiment, the energies of decay positions were measured. {rho} can be extracted from the energy spectrum by comparing it with that of Monte Carlo simulations. The experiment was carried out with the existing MEGA positron spectrometer, which consists of 180 strips of plastic scintillator forming two hollow barrels and 8 cylindrically shaped MWPCs arranged such that seven smaller ones surround a larger central one. To understand and elminate possible sources of systematic error, 6 modes of data were taken during the run. Following a brief discussion of the experimental setup, the authors will discuss the major systematic effects and the current status of the data analysis.

• OSTI ID: 243715
• Report Number(s): CONF-9304297--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 2 Vol. 38; ISSN BAPSA6; ISSN 0003-0503
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
DECAY AMPLITUDES
MUONS
POLARIZATION