${{\boldsymbol \mu}}$ DECAY PARAMETERS
($\mathit V−\mathit A$) theory predicts $\delta $ = 0.75.
$\bf{
0.75047 \pm0.00034}$
|
OUR AVERAGE
|
$0.75049$ $\pm0.00021$ $\pm0.00027$ |
|
1 |
|
TWST |
+ |
$0.7486$ $\pm0.0026$ $\pm0.0028$ |
|
2 |
|
SPEC |
+ |
• • • We do not use the following data for averages, fits, limits, etc. • • • |
$0.75067$ $\pm0.00030$ $\pm0.00067$ |
|
|
|
TWST |
+ |
$0.74964$ $\pm0.00066$ $\pm0.00112$ |
6G |
|
|
TWST |
+ |
|
|
3 |
|
|
|
$0.752$ $\pm0.009$ |
490k |
|
|
ASPK |
+ |
$0.782$ $\pm0.031$ |
|
|
|
|
|
$0.78$ $\pm0.05$ |
8354 |
|
|
HBC |
+ |
1
The quoted systematic error includes a contribution of 0.00006 (added in quadrature) from uncertainties on radiative corrections and on the Michel parameter $\eta $.
|
2
BALKE 1988 uses $\rho $ = $0.752$ $\pm0.003$.
|
3
VOSSLER 1969 has measured the asymmetry below 10 MeV. See comments about radiative corrections in VOSSLER 1969 .
|
|
References: |
| PRL 106 041804 |
Experimental Constraints on Left-Right Symmetric Models from Muon Decay |
| PR D78 032010 |
Precision Measurement of the Muon Decay Parameters ${{\mathit \rho}}$ and ${{\mathit \delta}}$ |
| PR D71 071101 |
Measurement of the Muon Decay Parameter $\delta $ |
| PR D37 587 |
Precise Measurement of the Asymmetry Parameter $\delta $ in Muon Decay |
| NC 63A 423 |
A Measurement of the Muon Decay Asymmetry at Low Energy |
| PR 166 1379 |
Measurement of the Muon Decay Spectrum with a Wire Spark Chamber Spectrometer |
| UCRL 9322 unpub. |
Momentum Dependence of the Asymmetry in Muon Decay |
| PR 119 1400 |
Momentum and Asymmetry Spectrum of ${{\mathit \mu}}$ Meson Decay |
|