Chiral low-energy constants L10 and C87 from hadronic τ decays
نویسندگان
چکیده
منابع مشابه
decays and chiral low - energy constants *
The branching ratios of the measured decay KL → ππee and of the still unmeasured decay K → ππee are calculated to next-to-leading order in Chiral Perturbation Theory (CHPT). Recent experimental results are used to determine two possible values of the combination (N r 16 −N17) of weak lowenergy couplings (LECs) from the O(p4) chiral Lagrangian. The obtained values are compared to the predictions...
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Using recent precise hadronic -decay data on the V A spectral function, and general properties of QCD such as analyticity, the operator product expansion, and chiral perturbation theory, we get accurate values for the QCD chiral order parameters L10ðM Þ and C87ðM Þ. These two low-energy constants appear at order p and p, respectively, in the chiral perturbation theory expansion of the V A corre...
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We study extractions of |Vus| based on finite energy sum rule (FESR) analyses of hadronic τ decay data. We show (i) that the “(0,0) spectral weight” implementation (proposed previously in the literature as a favorable version of this analysis) suffers from significant convergence problems, but (ii) that alternate implementations exist which bring these problems under control. Results based on p...
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Elvira Gámiz, Matthias Jamin, Antonio Pich, Joaquim Prades and Felix Schwab a Department of Physics & Astronomy, University of Glasgow Glasgow G12 8QQ, United Kingdom. b ICREA and IFAE, Universitat Autònoma de Barcelona E-08193 Bellaterra, Barcelona, Spain. c Departament de F́ısica Teòrica, IFIC, Universitat de València–CSIC Apt. de Correus 22085, E-46071 València, Spain. d Centro Andaluz de F́ıs...
متن کاملChiral Low-Energy Constants
The progress in determining the coupling constants of mesonic chiral Lagrangians is reviewed, with emphasis on the work performed in three successive European Networks (Eurodaphne I and II, Euridice). Reliable estimates of those constants are essential for making full use of next-to-next-to-leading-order calculations in chiral perturbation theory. The precision in the values of the strong coupl...
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ژورنال
عنوان ژورنال: Nuclear Physics B - Proceedings Supplements
سال: 2009
ISSN: 0920-5632
DOI: 10.1016/j.nuclphysbps.2008.12.040