Speaker
Description
We present our results of the $K_{l3}$ form factors on the volume of configuration 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 $a^{-1}=2.333$ GeV.
The $K_{l3}$ form factor at zero momentum transfer is obtained from fit results using the NLO formula in SU(3) chiral perturbation theory with NNLO analytic terms. In addition, we estimate systematic errors of the form factor, such as ones coming from excited state contamination and finite size effect.
We also determine the value of $|V_{us}|$ by combining our result with the experimental $K_{l3}$ form factor and check the consistency with the standard model prediction. The result is compared with the previous lattice calculations.
