we can choose the fitting range from $\tau=8$ to 15 to extract the form factor. However, as the pion mass decreases, the plateau signal becomes worse as exhibited in Fig. \[fig:Plateau\_PFF\_296\](a) for the lightest case of $M_\pi\approx 296$ MeV where the ratio $R(\tau)$ at the two smallest momentum transfers, $Q^2({\rm GeV^2})=0.01841$ and $0.04237$, is shown. We then choose larger values for the starting point of the fitting range for better suppression of excited states at lighter pion masses. The error is estimated by the jackknife method using 10 configurations corresponding to 50 hybrid molecular dynamics time units as the bin size after checking saturation of the magnitude of error as function of bin size. Fit results for the pion form factor are listed in Table \[table:PFF\_dataset1\].

   $\kappa_{ud}$   $\kappa_{s}$   $M_\pi$ (MeV)   $M_K$ (MeV)   \#conf measured       $\theta$
  --------------- -------------- --------------- ------------- ----------------- ------------------
      0.13700         0.1364           702            792             40          0.18423, 0.28112
      0.13727         0.1364           570            716             40          0.18467, 0.28265
      0.13754         0.1364           411            637             40          0.18585, 0.28672
      0.13770         0.1364           296            596             160         0.18814, 0.29450

  : Statistics of data set I.[]{data-label="table:stat_dataset1"}

[c c c c c c c c c c]{}\
$Q^2$(GeV$^2$) & 0.01842 & 0.04237 & 0.1163 & 0.1258 & 0.1682 & 0.3651 & 0.7302\
