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arXiv · hep-ph/9711445

P-odd observables at the $Υ$ peak

J. Bernabeu·F. J. Botella·O. Vives
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Abstract

We study the $γ$-Z interference in the process $e^+ e^-\to Υ\to τ^+ τ^-$ as a means to measure the neutral current coupling of the b-quark. The helicity amplitudes are calculated from resonant and background diagrams and the spin density matrix of the final state is discussed. The spin analyzer of the $τ$'s is illustrated with the decays $πν$ and $ρν\to (ππ) ν$. With $10^8 Υ$ a sensitivity to $g_V^b$ of a few per cent could be reachable.

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J. Bernabeu, F. J. Botella, O. Vives. 1997-11-24. P-odd observables at the $Υ$ peak. https://doi.org/10.1007/s100529801007

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