Observations Concerning the Magnitude of t \bar{t} Threshold Effects on Electroweak Parameters

Abstract

We discuss a recent analysis of $t\bar{t}$ threshold effects and its implications for the determination of electroweak parameters. We show that the new formulation, when applied to the $\rho$ parameter for $m_t\approx 158$~GeV, gives a result of similar magnitude to those previously obtained. In fact, it is quite close to our ``resonance'' calculation. We also present a simple estimate of the size of the threshold effects based on an elementary Bohr-atom model of $t\bar{t}$ resonances.

11 pages, latex, DESY 93-194, NYU-Th-93/12/01

References in corpus (5)

• $O(\alpha {\alpha }_s^2)$ correction to the electroweak $\rho$ parameter
• Rigourous QCD Evaluation of Spectrum and Ground State Properties of Heavy Quarkonium Systems; with a Precision Determination of the bottom quark mass and of the eta-b mass
• Incorporation of QCD Effects in Basic Corrections of the Electroweak Theory
• On the Evaluation of Threshold Effects in Processes Involving Heavy Quarks
• On the Precision of the Computation of the QCD Corrections to Electroweak Vacuum Polarizations

Cited by in corpus (3)

• Unitarity and the scale of fermion mass generation
• Comment on the Dispersion Relations used to Calculate $\Delta \rho$
• On the Choice of Dispersion Relation to Calculate the QCD Correction to $Γ(H\to \ell^+\ell^-)