Non--decoupling, triviality and the $\rho$ parameter

Abstract

The dependence of the $\rho$ parameter on the mass of the Higgs scalar and the top quark is computed non--perturbatively using the $1/N_F$ expansion in the standard model. We find an explicit expression for the $\rho$ parameter that requires the presence of a physical cutoff. This should come as no surprise since the theory is presumably trivial. By taking this cutoff into account, we find that the $\rho$ parameter can take values only within a limited range and has finite ambiguities that are suppressed by inverse powers of the cutoff scale, the so called ``scaling--violations". We find that large deviations from the perturbative results are possible, but only when the cutoff effects are also large.

16pp, Figures NOT included, harvmac, minor modifications incl. wording, refs., UCLA/92/TEP/23,OHSTPY-HEP-T-92-008

References in corpus (1)

• Non--perturbative evidence for non--decoupling of heavy fermions

Cited by in corpus (7)

• The Gauged Vector Model in Four-Dimensions: Resolution of an Old Problem?
• Non-decoupling effects due to a dimensionful coupling
• Resummed corrections to the ρparameter due to a finite width of the top quark
• Resummed corrections to the ρparameter in the complex mass scheme
• Monte-Carlo study of the $\Delta \rho$ parameter
• Heavy top renormalon contribution to fermion propagators
• Triviality, perturbation theory and $Z\to b\overline{b}$