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arXiv · 1601.05998

Leptonic decay-constant ratio $f_K/f_\pi$ from lattice QCD using 2+1 clover-improved fermion flavors with 2-HEX smearing

Stephan Dürr·Zoltán Fodor·Christian Hoelbling·Stefan Krieg·Laurent Lellouch·Thomas Lippert·Thomas Rae·Andreas Schäfer·Enno E. Scholz·Kálmán K. Szabó·Lukas Varnhorst
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Abstract

We present a calculation of the leptonic decay-constant ratio $f_K/f_\pi$ in 2+1 flavor QCD. Our data set includes five lattice spacings and pion masses reaching down below the physical one. Special emphasis is placed on a careful study of all systematic uncertainties, especially the continuum extrapolation. Our result is perfectly compatible with the first-row unitarity constraint of the Standard Model.

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Stephan Dürr, Zoltán Fodor, Christian Hoelbling, Stefan Krieg, Laurent Lellouch, Thomas Lippert, Thomas Rae, Andreas Schäfer, Enno E. Scholz, Kálmán K. Szabó, Lukas Varnhorst. 2016-01-22. Leptonic decay-constant ratio $f_K/f_\pi$ from lattice QCD using 2+1 clover-improved fermion flavors with 2-HEX smearing. https://doi.org/10.1103/physrevd.95.054513

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