DISPERSION-RELATIONS FOR VACUUM-POLARIZATION FUNCTIONS IN ELECTROWEAK PHYSICS

被引:86
作者
KNIEHL, BA
SIRLIN, A
机构
[1] UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706
[2] NYU,DEPT PHYS,NEW YORK,NY 10003
关键词
D O I
10.1016/0550-3213(92)90232-Z
中图分类号
O412 [相对论、场论]; O572.2 [粒子物理学];
学科分类号
摘要
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(alpha) and O(alpha-alpha(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-r. 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 from non-perturbative ttBAR threshold effects.
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收藏
页码:141 / 148
页数:8
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