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arXiv · 1001.4692

The ratio FK/Fpi in QCD

S. Durr·Z. Fodor·C. Hoelbling·S. D. Katz·S. Krieg·T. Kurth·L. Lellouch·T. Lippert·A. Ramos·K. K. Szabo
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Abstract

We determine the ratio FK/Fpi in QCD with Nf=2+1 flavors of sea quarks, based on a series of lattice calculations with three different lattice spacings, large volumes and a simulated pion mass reaching down to about 190 MeV. We obtain FK/Fpi=1.192 +/- 0.007(stat) +/- 0.006(syst). This result is then used to give an updated value of the CKM matrix element |Vus|. The unitarity relation for the first row of this matrix is found to be well observed.

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S. Durr, Z. Fodor, C. Hoelbling, S. D. Katz, S. Krieg, T. Kurth, L. Lellouch, T. Lippert, A. Ramos, K. K. Szabo. 2010-01-26. The ratio FK/Fpi in QCD. https://doi.org/10.1103/physrevd.81.054507

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