ansatz. These differences are also visible in the panels (a) and (b) as indicated in the magnified region of small four-momentum transfers.

The NLO ChPT fit at $M_\pi=296$ MeV has a smaller $\chi^2/d.o.f$ compared to that of monopole fit tabulated in Table \[table:BothDataSet\_r2\]. This is not the case at the pion mass of 411 MeV, however, where $\chi^2/d.o.f$ of the NLO ChPT fit is significantly larger than that of the monopole fit. As we shall discuss below in Fig. \[fig:R2\_ChPT\_NLO\_411\_Qsq010\](a) for the SU(2) case, this is due to an upward curvature of the form factor data as $Q^2$ increases to 0.08 and 0.10 GeV$^2$. Higher order terms in $Q^2$ need to be included in order to explain the behavior of our data for the form factor at 411 MeV.

  ------------------- ------------------ ---------------- ------------------------------------- ------------------ ---------------- ------------------------------------- --
   $M_\pi (\rm MeV)$                                                                                                                                                      
                       $l^r_6(\mu=1/a)$   $\chi^2/d.o.f$   $\left< r^2 \right>_{phys}$(fm$^2$)   $L^r_9(\mu=1/a)$   $\chi^2/d.o.f$   $\left< r^2 \right>_{phys}$(fm$^2$)  
          296            -0.01238(66)        0.29(10)                   0.457(18)                  0.00577(33)         0.29(10)                   0.462(18)               
          411            -0.01408(45)        2.38(27)                   0.502(12)                  0.00666(22)         2.37(27)                   0.509(12)               
  ------------------- ------------------ ---------------- ------------------------------------- ------------------ ---------------- ------------------------------------- --

  : NLO ChPT fit of $G_\pi(Q^2)$ utilizing $M_\pi^2/f_\pi^2$ as the expansion parameter at fixed pion mass $M_\pi$. Values of the decay constant at the simulation points are $f_\pi 