2-LOOP CORRECTIONS TO THE HEAVY TOP LIMIT IN THE RHO-PARAMETER

被引：21

作者：

DEGRASSI, G

FANCHIOTTI, S

FERUGLIO, F

GAMBINO, P

VICINI, A

机构：

[1] IST NAZL FIS NUCL,I-35131 PADUA,ITALY

[2] CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND

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

来源：

PHYSICS LETTERS B | 1995年 / 350卷 / 01期

关键词：

D O I：

10.1016/0370-2693(95)00268-P

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

The top quark contribution to two-loop, purely electroweak radiative corrections is investigated in the case of the rho parameter, extracted from the ratio of neutral to charged current amplitudes in low-energy neutrino-lepton scattering. It is shown that the order O(G(mu)(2)m(t)(2)m(Z)(2) ) contribution is numerically comparable and shares the same sign with the leading O(G(mu)(2)m(t)(4)) term, for realistic values of the top and Higgs masses. The result raises doubts on the reliability of the heavy top approximation in the two-loop contributions to electroweak observables. A naive extrapolation of this result to LEP observables would suggest an overall two-loop electroweak contribution close to the ultimate experimental sensitivity.

引用

页码：75 / 84

页数：10