1997/06/11 by Kaoru Hagiwara, Dieter Haidt, Seiji Matsumoto · 4 citations
Computer Science · Physics and Astronomy · #Computational Physics and Python Applications #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1007/s100520050126
published as Eur.Phys.J.C2:95-122,1998 · 48 pages, Latex, uses axodraw.sty, 32 Postscript figures, to be published in Z.Phys.C
arxiv created 1997/06/11 · openalex publication_date 1998/03/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
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 αs(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 ∼ 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 αs and the QED effective coupling α(mZ2). 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 α(mZ2) are discussed. Anticipating uncertainties of 0.00020 for \sbar2(mZ2), 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 α(mZ2).