**
**

The probability for 2
measurements to disagree by 3.5 standard deviations (3.5s) is
much less than 0.1%. This means that in a sample of 1000 measurements, it is
unlikely for any 2 of
the 1000 measurements to disagree by 3.5s or more.
And for any random
comparison of 2 measurements, it is highly unlikely to observe such a large disagreement. |

SLAC and CERN results for asymmetry
measurements in the interactions of ZThe SLAC and CERN measurements for the leptonic asymmetries, A^{0} particles with b-quarks and
leptons. _{l},
are combined and are represented by the red band. SLD measures the b-quark asymmetry
parameter, A_{b}, directly (because of its polarized electron beam) and this
result is shown as the green band. The CERN experiments measure a forward-backward
asymmetry in Z^{0} decays to b-quark pairs and this asymmetry is proportional to
the product of A_{b} times A_{l}. This CERN result is shown as the
blue band. The Standard Model predicts that A_{b} should be equal to 0.935,
and that A_{l} should be in the range from 0.136 (for a Higgs mass of 1000 GeV) to
0.147 (for a Higgs mass of 113 GeV). The widths of the bands shown represent +/- 1
standard deviation.SLAC and CERN's A _{l }results favor a light (Standard
Model) Higgs and SLD's A_{b} result is consistent with the Standard Model
prediction. CERN's forward-backward b-quark asymmetry result favors a heavy
(Standard Model) Higgs. The self-consistency of these three data measurements
and the Standard Model predictions is marginal and has only an 0.2% probability to
give the large observed c^{2}/dof=12.4/2. Of the three data measurements, the
simplest and most reliable one experimentally is the A_{l} result. In
particular, SLD's very precise measurement of A_{l} from its left-right asymmetry
(A_{LR}) measurement results from a simple counting measurement and is very
robust. |

Last updated 04-09-2001