pdgLive

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

$\xi ({{\mathit \rho}}$) PARAMETER

INSPIRE JSON (beta) PDGID:

($\mathit V−\mathit A$) theory predicts $\xi ({{\mathit \rho}}$) = $1$.

VALUE

EVTS

DOCUMENT ID

TECN

COMMENT

$\bf{ 0.994 \pm0.008}$

OUR FIT

$\bf{ 0.994 \pm0.009}$

OUR AVERAGE

$0.987$ $\pm0.012$ $\pm0.011$

59k

ALEP

1991--1995 LEP runs

$0.99$ $\pm0.12$ $\pm0.04$

SLD

1993--1995 SLC runs

$0.995$ $\pm0.010$ $\pm0.003$

66k

CLEO

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

$1.022$ $\pm0.028$ $\pm0.030$

1.7k

ARG

${\it{}E}^{\it{}ee}_{\rm{}cm}$= $9.4 - 10.6$ GeV

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

$1.045$ $\pm0.058$ $\pm0.032$

ALEP

Repl. by HEISTER 2001E

$1.03$ $\pm0.11$ $\pm0.05$

ALEP

1990+1991 LEP run

¹	ALBRECHT 1994E measure the square of this quantity and use the sign determined by ALBRECHT 1990I to obtain the quoted result.

²	Superseded by BUSKULIC 1995D.

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