Dimension-six CP conserving operators of the third family quarks and their effects on collider observables
Dimension-six CP conserving operators of the third family quarks and their effects on collider observables
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DOI：
10.1103/physrevd.56.467
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发表时间：
1997-02
影响因子：
5
通讯作者：
K. Whisnant;Jin Min Yang;B. Young;X. Zhang
中科院分区：
文献类型：
--
作者：
K. Whisnant;Jin Min Yang;B. Young;X. Zhang
我们列出了所有可能的六维 CP 守恒 SUc(3)xSU(L)(2)xU(Y)(1) 不变算子，涉及第三族夸克，这些夸克可以由更高尺度的新物理产生。给出了电弱规范对称破缺后这些算子的表达式以及杆上的感应有效耦合 Wt(b)、杆上的 Xb(b) 和杆上的 Xt(t) (X = Z、gamma、g、H)。所有这些算子对 CERN LEP I 处的可观测量 R-b 和 A(FB)(b)、LEP II 处的 sigma(e(+)e(-) --> ) 和 A(FB)(b)、下一个线性对撞机 (NLC) 处的 sigma(e(+)e(-) --> ) 和 A(FB)(t) 的树级贡献的解析表达式。以及 Fermilab Tevatron 升级中的 sigma(--> + X) 均已提供。讨论了这些算子对不同电弱可观测量的影响并给出了数值例子。数值分析表明，在 LEP I 上 R-b 和 A(FB)(b) 允许的耦合区域中，一些新的物理算子仍然可以在 LEP II、Tevatron 和 NLC 上做出重大贡献。
We list all possible dimension-six CP-conserving SUc(3)xSU(L)(2)xU(Y)(1)-invariant operators involving the third-family quarks which could be generated by new physics at a higher scale. Expressions for these operators after electroweak gauge symmetry breaking and the induced effective couplings Wt(b) over bar, Xb(b) over bar, and Xt(t) over bar (X = Z, gamma,g, H) are presented. Analytic expressions for the tree level contributions of all these operators to the observables R-b and A(FB)(b) at CERN LEP I, sigma(e(+)e(-) --> ) and A(FB)(b) at LEP II, sigma(e(+)e(-) --> ) and A(FB)(t) at the Next Linear Collider (NLC). as well as sigma( --> + X) at the Fermilab Tevatron upgrade, are provided. The effects of these operators on different electroweak observables are discussed and numerical examples presented. Numerical analyses show that in the coupling region allowed by R-b and A(FB)(b) at LEP I, some of the new physics operators can still have significant contributions at LEP II, the Tevatron, and the NLC.