EFFECT OF THE T(T)OVER-BAR THRESHOLD ON ELECTROWEAK PARAMETERS

被引：88

作者：

KNIEHL, BA ^{[1
]}

SIRLIN, A ^{[1
]}

机构：

[1] NYU,DEPT PHYS,NEW YORK,NY 10003

来源：

PHYSICAL REVIEW D | 1993年 / 47卷 / 03期

关键词：

D O I：

10.1103/PhysRevD.47.883

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Threshold effects in e+e- --> ttBAR induce contributions to key electroweak parameters such as DELTArho, DELTAr, and sin2theta(W) beyond the scope of perturbative calculations of O(alpha) and O(alphaalpha(s)). We quantitatively analyze these effects using once-subtracted dispersion relations which manifestly satisfy relevant Ward identities. The derivation and properties of the dispersion relations are discussed at some length. We find that the threshold effects enhance the familiar perturbative O(alphaalpha(s)) corrections by between 25% and 40%, depending on the t-quark mass. The shift in the predicted value of the W-boson mass due to the threshold effects ranges from -8 MeV at m(t) = 91 GeV to -45 MeV at m(t) = 250 GeV.

引用

页码：883 / 893

页数：11

共 53 条

[11] SINGULARITIES AND DISCONTINUITIES OF FEYNMAN AMPLITUDES [J].