83 research outputs found
Analysis of Electroweak Precision Data and Prospects for Future Improvements
We update our previous work on an analysis of the electroweak data by
including new and partly preliminary data available up to the 1996 summer
conferences. The new results on the Z partial decay widths into b and c hadrons
now offer a consistent interpretation of all data in the minimal standard
model. The value extracted for the strong interaction coupling constant
\alpha_s(mZ) agrees well with determinations in other areas. New constraints on
the universal parameters S, T and U are obtained from the updated measurements.
No signal of new physics is found in the S,T,U analysis once the SM
contributions with mt \sim 175GeV and those of not a too heavy Higgs boson are
accounted for. The naive QCD-like technicolor model is now ruled out at the
99%CL even for the minimal model with SU(2)_{TC}. In the absence of a
significant new physics effect in the electroweak observables, constraints on
masses of the top quark, mt, and Higgs boson, mH, are derived as a function of
\alpha_s and the QED effective coupling . The preferred
range of mH depends rather strongly on the actual value of mt: mH<360 GeV for
mt=170GeV, while mH>130GeV for mt=180GeV at 95%CL. Prospects due to forthcoming
improved measurements of asymmetries, the mass of the weak boson W mW, mt and
are discussed. Anticipating uncertainties of 0.00020 for
\sbar^2(m_Z^2), 20MeV for mW, and 2GeV for mt, the new physics contributions
to the S,T,U parameters will be constrained more severely, and, within the SM,
the logarithm of the Higgs mass can be constrained to about +-0.35. The better
constraints on S,T,U and on mH within the minimal SM should be accompanied with
matching precision in .Comment: 48 pages, Latex, uses axodraw.sty, 32 Postscript figures, to be
published in Z.Phys.
SESSION 6: QCD and the Standard Model in Neutrino Physics
- Bubble chamber neutrino experiments and the Standard Model Parameter
The Discovery of Weak Neutral Currents
The beginning of high energy neutrino physics at CERN is outlined followed by the presentation of the discovery of weak neutral currents in the bubble chamber Gargamelle
- …