Implications of LEP/SLD Data for New Physics in Zbb̄ Couplings
نویسندگان
چکیده
The combined LEP/SLD data on the bb̄ forward-backward asymmetry from the Z-pole measurements may imply the presence of new physics in the Zbb̄ couplings. In general, the effect of new physics can be parameterized by SUC(3)× SUL(2)×UY (1) invariant higher dimensional operators. By fitting the recently announced LEP/SLD data on Ab and Rb, the size of the coupling strengths of these operators can be determined. We also found that the new physics operators can be divided into two types, depending on their Higgs field content. The ones involving the Higgs have very mild effects at higher energy colliders, while the other type which do not contain the Higgs field can show significantly large effects on bb̄ production at LEP II, tt̄ production at the NLC and single top production at the Tevatron. The preliminary data from the LEP II measurements disfavors the second type of operators. Typeset using REVTEX
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