ChPT parameters from τ-decay data

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• 作者：A. Rodrí ; guez-Sá ; nchez^a ; ¹ ; M. Gonzá ; lez-Alonso^b ; A. Pich^a
• 关键词：Chiral Perturbation Theory ; Operator Product Expansion ; Sum Rules ; τ decays
• 刊名：Nuclear and Particle Physics Proceedings
• 出版年：2016
• 出版时间：January-March 2016
• 年：2016
• 卷：270-272
• 期：Complete
• 页码：108-112
• 全文大小：404 K

文摘

Using the updated ALEPH V−A$V-A$ spectral function from τ   decays, we determine the lowest spectral moments of the left-right correlator and extract dynamical information on order parameters of the QCD chiral symmetry breaking. Uncertainties associated with violations of quark-hadron duality are estimated from the data, imposing all known short-distance constraints on a resonance-based parametrization. Employing proper pinched weight functions, we obtain an accurate determination of the effective chiral couplings $L_{10}^{\mathrm{eff}}$ and $C_8^{\mathrm{eff}}7$ and the dimension-six and -eight contributions in the Operator Product Expansion.