# Limit on ${{\boldsymbol W}_{{L}}}-{{\boldsymbol W}_{{R}}}$ Mixing Angle $\zeta$ INSPIRE search

Lighter mass eigenstate ${{\mathit W}_{{1}}}$ = ${{\mathit W}_{{L}}}$cos $\zeta −{{\mathit W}_{{R}}}$sin$\zeta$. Light ${{\mathit \nu}_{{R}}}$ assumed unless noted. Values in brackets are from cosmological and astrophysical considerations.
VALUE CL% DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
$-0.020\text{ to }0.017$ 90
 2011
TWST ${{\mathit \mu}}$ $\rightarrow$ ${{\mathit e}}{{\mathit \nu}}{{\overline{\mathit \nu}}}$
$<0.022$ 90
 2008
TWST ${{\mathit \mu}}$ $\rightarrow$ ${{\mathit e}}{{\mathit \nu}}{{\overline{\mathit \nu}}}$
$<0.12$ 95 1
 1999 D
OPAL ${{\mathit \tau}}$ decay
$<0.013$ 90 2
 1999
RVUE Electroweak
$<0.0333$ 3
 1997
RVUE ${{\mathit \mu}}$ decay
$<0.04$ 90 4
 1992
CCFR ${{\mathit \nu}}{{\mathit N}}$ scattering
$-0.0006\text{ to }0.0028$ 90 5
 1991
RVUE
$\text{[none 0.00001 - 0.02]}$ 6
 1989 B
ASTR SN 1987A
$<0.040$ 90 7
 1986
ELEC ${{\mathit \mu}}$ decay
$-0.056\text{ to }0.040$ 90 7
 1986
ELEC ${{\mathit \mu}}$ decay
1  ACKERSTAFF 1999D limit is from ${{\mathit \tau}}$ decay parameters.
2  CZAKON 1999 perform a simultaneous fit to charged and neutral sectors.
3  The quoted limit is from ${{\mathit \mu}}$ decay parameters. BARENBOIM 1997 also evaluate limit from ${{\mathit K}_{{L}}}-{{\mathit K}_{{S}}}$ mass difference.
4  MISHRA 1992 limit is from the absence of extra large-$\mathit x$, large-$\mathit y$ ${{\overline{\mathit \nu}}_{{\mu}}}$ ${{\mathit N}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{\mu}}}$ X events at Tevatron, assuming left-handed ${{\mathit \nu}}$ and right-handed ${{\overline{\mathit \nu}}}$ in the neutrino beam. The result gives $\zeta {}^{2}(1−2{{\mathit m}^{2}}_{{{\mathit W}_{{1}}}}/{{\mathit m}^{2}}_{{{\mathit W}_{{2}}}})<0.0015$. The limit is independent of ${{\mathit \nu}_{{R}}}$ mass.
5  AQUINO 1991 limits obtained from neutron lifetime and asymmetries together with unitarity of the CKM matrix. Manifest left-right asymmetry is assumed.
6  BARBIERI 1989B limit holds for ${\mathit m}_{{{\mathit \nu}_{{R}}}}{}\leq{}$10 MeV.
7  First JODIDIO 1986 result assumes ${\mathit m}_{{{\mathit W}_{{R}}}}=\infty{}$, second is for unconstrained ${\mathit m}_{{{\mathit W}_{{R}}}}$.
References:
 BUENO 2011
PR D84 032005 Precise Measurement of Parity Violation in Polarized Muon Decay
 MACDONALD 2008
PR D78 032010 Precision Measurement of the Muon Decay Parameters ${{\mathit \rho}}$ and ${{\mathit \delta}}$
 ACKERSTAFF 1999D
EPJ C8 3 Measurement of the Michel Parameters in Leptonic ${{\mathit \tau}}$ Decays
 CZAKON 1999
PL B458 355 Low-Energy Physics and Left-Right Symmetry: Bounds on the Model Parameters
 BARENBOIM 1997
PR D55 4213 Constraints on the W$_{R}$ Mass and $\mathit CP$ Violation in Left $−$ Right Models
 MISHRA 1992
PRL 68 3499 Search for Right Handed Coupling in ${{\mathit \nu}}{{\mathit n}}$ Scattering
 AQUINO 1991
PL B261 280 Bounds on Manifest Left-Right Symmetry from Neutron $\beta$ Decay
 BARBIERI 1989B
PR D39 1229 Limits on Righthanded Interactions from SN1987a Observations
 JODIDIO 1986
PR D34 1967 Search for Right Handed Currents in Muon Decay