Dispersion relations for vacuum-polarization functions in electroweak physics
Kniehl, B A [Wisconsin Univ., Madison, WI (United States). Dept. of Physics]; [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]; Sirlin, A [New York Univ., NY (United States). Dept. of Physics]
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; WEINBERG LEPTON MODEL; VACUUM POLARIZATION; FERMIONS; PERTURBATION THEORY; WARD IDENTITY; DISPERSION RELATIONS; QUANTUM ELECTRODYNAMICS; QUANTUM CHROMODYNAMICS; REST MASS; RENORMALIZATION; RADIATIVE CORRECTIONS; FUNCTIONS; 662210; UNIFIED THEORIES AND MODELS
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.).
Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
OSTI; NTIS (US Sales Only); INIS
Germany
1991-09-01
English
Technical Report
Other Information: PBD: Sep 1991
Medium: X; Size: 11 p.
ON: DE92759320; CNN: Contract DE-AC02-76ER00881; Grant PHY-90-17585
DESY-91-103; MAD/PH-670
Other: ON: DE92759320; CNN: Contract DE-AC02-76ER00881; Grant PHY-90-17585; TRN: DE9200739
DEN; SCA: 662210; PA: DEN-92:000739; SN: 92000645618
2008-02-12
10114470