Abstract
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 indentities. We show that in perturbation theory to O({alpha}) and O({alpha}{alpha}{sub 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 {Delta}{rho} and {Delta}{rho}. 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 contributions arising form non-perturbative tanti t threshold effects. (orig.).
Kniehl, B A;
[1]
Sirlin, A
[2]
- Wisconsin Univ., Madison, WI (United States). Dept. of Physics
- New York Univ., NY (United States). Dept. of Physics
Citation Formats
Kniehl, B A, and Sirlin, A.
Dispersion relations for vacuum-polarization functions in electroweak physics.
Germany: N. p.,
1991.
Web.
Kniehl, B A, & Sirlin, A.
Dispersion relations for vacuum-polarization functions in electroweak physics.
Germany.
Kniehl, B A, and Sirlin, A.
1991.
"Dispersion relations for vacuum-polarization functions in electroweak physics."
Germany.
@misc{etde_10114470,
title = {Dispersion relations for vacuum-polarization functions in electroweak physics}
author = {Kniehl, B A, and Sirlin, A}
abstractNote = {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 indentities. We show that in perturbation theory to O({alpha}) and O({alpha}{alpha}{sub 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 {Delta}{rho} and {Delta}{rho}. 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 contributions arising form non-perturbative tanti t threshold effects. (orig.).}
place = {Germany}
year = {1991}
month = {Sep}
}
title = {Dispersion relations for vacuum-polarization functions in electroweak physics}
author = {Kniehl, B A, and Sirlin, A}
abstractNote = {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 indentities. We show that in perturbation theory to O({alpha}) and O({alpha}{alpha}{sub 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 {Delta}{rho} and {Delta}{rho}. 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 contributions arising form non-perturbative tanti t threshold effects. (orig.).}
place = {Germany}
year = {1991}
month = {Sep}
}