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arXiv · hep-ph/9905478

The Z -> bb decay asymmetry and flavor changing neutral currents

Michael S. Chanowitz
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Abstract

The measured value of A_b, the Z \bar bb asymmetry parameter, disagrees with the Standard Model at 99% confidence level. If genuine the discrepancy could indicate new interactions unique to third generation quarks, implying enhanced Z penguin amplitudes. Enhanced rates are predicted for rare K and B decays, such as K^{+} --> pi^{+}\bar nu nu, K_{L} --> pi^{0}\bar nu nu, B --> X_{s}\bar nu nu, and B_{s} --> \bar mu mu. Measurements of epsilon^{\prime}/epsilon then imply QCD penguin amplitudes must also be similarly enhanced. The Higgs sector of an SU(2)_L x SU(2)_R gauge theory has some of the features needed to explain these phenomena and would also imply right-handed penguin amplitudes.

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Michael S. Chanowitz. 1999-07-06. The Z -> bb decay asymmetry and flavor changing neutral currents. https://arxiv.org/abs/hep-ph/9905478

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