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arXiv · 2002.01684

$K_{l3}$ form factors in $N_f = 2+1$ QCD at physical point on large volume

Junpei Kakazu·Ken-ichi Ishikawa·Naruhito Ishizuka·Yoshinobu Kuramashi·Yoshifumi Nakamura·Yusuke Namekawa·Yusuke Taniguchi·Naoya Ukita·Takeshi Yamazaki·Tomoteru Yoshié
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Abstract

We present our results of the $K_{l3}$ form factors on the volume whose spatial extent is more than $L=$10 fm, with the physical pion and kaon masses using the stout-smearing clover $N_f = 2+1$ quark action and Iwasaki gauge action at $a^{-1}\approx2.3$ GeV. The $K_{l3}$ form factor at zero momentum transfer is obtained from fit based on the next-to-leading (NLO) formula in SU(3) chiral perturbation theory. We estimate systematic errors of the form factor, mainly coming from the finite lattice spacing effect. We also determine the value of $|V_{us}|$ by combining our result with the experiment and check the consistency with the standard model prediction. The result is compared with the previous lattice calculations.

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Junpei Kakazu, Ken-ichi Ishikawa, Naruhito Ishizuka, Yoshinobu Kuramashi, Yoshifumi Nakamura, Yusuke Namekawa, Yusuke Taniguchi, Naoya Ukita, Takeshi Yamazaki, Tomoteru Yoshié. 2020-02-05. $K_{l3}$ form factors in $N_f = 2+1$ QCD at physical point on large volume. https://arxiv.org/abs/2002.01684

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