#### $\xi$ ${\times }$ (${{\mathit \mu}}$ LONGITUDINAL POLARIZATION) ${\times }$ $\delta$ $/$ $\rho$

VALUE CL% DOCUMENT ID TECN CHG  COMMENT
$1.00179$ ${}^{+0.00156}_{-0.00071}$ 1
 2011
TWST + Surface ${{\mathit \mu}^{+}}$ beam
• • We do not use the following data for averages, fits, limits, etc. • •
$>0.99682$ 90 2
 1986
SPEC + TRIUMF
$>0.9966$ 90 3
 1985
SPEC + ${{\mathit \mu}}$ -spin rotation
$>0.9959$ 90
 1983
SPEC + 11 kG
 1 BAYES 2011 obtains the limit $>$ 0.99909 (90$\%$ CL) with the constraint that $\xi {\times }({{\mathit \mu}}$ LONGITUDINAL POLARIZATION)${\times }\delta /\rho$ ${}\leq{}$ 1.0.
 2 JODIDIO 1986 includes data from CARR 1983 and STOKER 1985 . The value here is from the erratum.
 3 STOKER 1985 find ($\xi {}P_{\mu }{}\delta /\rho$) $>$0.9955 and $>$0.9966, where the first limit is from new ${{\mathit \mu}}$ spin-rotation data and the second is from combination with CARR 1983 data. In $\mathit V−\mathit A$ theory, ($\delta /\rho$) = 1.0.
References:
 BAYES 2011
PRL 106 041804 Experimental Constraints on Left-Right Symmetric Models from Muon Decay
 Also
PR D85 092013 Precision Muon Decay Measurements and Improved Constraints on the Weak Interaction
 JODIDIO 1986
PR D34 1967 Search for Right Handed Currents in Muon Decay
 Also
PR D37 237 (erratum) Search for Right Handed Currents in Muon Decay
 STOKER 1985
PRL 54 1887 Search for Right Handed Currents by Means of Muon Spin Rotation
 CARR 1983
PRL 51 627 Search for Right Handed Currents in Muon Decay