Dispersion relations for vacuum-polarization functions in electroweak physics

We propose a class of once-subtracted dispersion relations for the vacuum-polarization functions of massive fermions, in which the subtraction constants are determined explicitly from Ward identities. We show that in perturbation theory to O(α) and O( αα s ) this approach, the alternative dispersion...

Full description

Saved in:
Bibliographic Details
Published inNuclear physics. B Vol. 371; no. 1; pp. 141 - 148
Main Authors Kniehl, Bernd A., Sirlin, Alberto
Format Journal Article
LanguageEnglish
Published Amsterdam Elsevier B.V 02.03.1992
Elsevier
Subjects
Classical and quantum physics: mechanics and fields
Exact sciences and technology
Physics
Theory of quantized fields
Vacuum polarization
Electroweak interaction
Quantum field theory
Dispersion relation
Online AccessGet full text

Cover

More Information
Summary:We propose a class of once-subtracted dispersion relations for the vacuum-polarization functions of massive fermions, in which the subtraction constants are determined explicitly from Ward identities. We show that in perturbation theory to O(α) and O( αα s ) this approach, the alternative dispersion relations proposed by Chang, Gaemers and van Neerven, and dimensional regularization all give the same contributions to electroweak observables such as Δϱ and Δr. The threshold behaviours of the subtraction integrands are, however, very different and the two dispersion methods are expected to lead to significantly variant estimates of contributionsarising from non-perturbative tt threshold effects.
ISSN:0550-3213
1873-1562
DOI:10.1016/0550-3213(92)90232-Z