pdgLive

${{\mathit \tau}}$-DECAY PARAMETERS

$\eta ({{\mathit e}}$ or ${{\mathit \mu}}$) PARAMETER

($\mathit V−\mathit A$) theory predicts $\eta $ = $0$.

VALUE

EVTS

DOCUMENT ID

TECN

COMMENT

$\bf{ 0.013 \pm0.020}$

OUR FIT

$\bf{ 0.015 \pm0.021}$

OUR AVERAGE

$0.012$ $\pm0.026$ $\pm0.004$

81k

ALEP

1991--1995 LEP runs

$-0.005$ $\pm0.036$ $\pm0.037$

DLPH

1992--1995 runs

$0.027$ $\pm0.055$ $\pm0.005$

46k

OPAL

1990--1995 LEP runs

$0.27$ $\pm0.14$

54k

L3

$1991 - 1995$ LEP runs

$-0.13$ $\pm0.47$ $\pm0.15$

SLD

1993--1995 SLC runs

$-0.015$ $\pm0.061$ $\pm0.062$

31k

CLEO

${\it{}E}^{\it{}ee}_{\rm{}cm}$= $10.6$ GeV

$0.03$ $\pm0.18$ $\pm0.12$

8.2k

ARG

${\it{}E}^{\it{}ee}_{\rm{}cm}$= $9.5 - 10.6$ GeV

• • We do not use the following data for averages, fits, limits, etc. • •

$0.25$ $\pm0.17$ $\pm0.11$

18k

L3

Repl. by ACCIARRI 1998R

$-0.04$ $\pm0.15$ $\pm0.11$

ALEP

Repl. by HEISTER 2001E

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