correlation functions by the exponential fit as $\langle {\cal N}^\pm_i(t_{\rm src}+T)
\overline{{\cal N}^\pm_i}(t_{\rm src}) \rangle
= C \exp(-E_i^\pm T)$ in the large-$T$ region. The value at each hopping parameter is found to coincide with that in the original paper by the CP-PACS collaboration [@AliKhan:2001tx], with deviations of 0.1% to 1%. We here perform simple linear chiral extrapolations for $E_{1,2}^\pm$. The chirally extrapolated values as well as those at each hopping parameter for $E_{1,2}^\pm$ in lattice unit are listed in Table \[fittedval\]. Although the mass $E_1^+$ of the ground-state positive-parity nucleon at the chiral limit is overestimated in our analysis ($a^{-1}=1.267$ GeV), this failure comes from our simple linear fit.

![\[AxialVectorC\] The renormalized vector and axial charges of the positive- and the negative-parity nucleons are plotted as a function of the squared pion mass $m_\pi^2$. [**upper panel**]{}: The results of the vector charges. The solid line is drawn at ${g}_V=1$ for reference. [**lower panel**]{}: The results of the axial charges. The solid line is drawn at ${g}_A=1.26$ and the dashed line is drawn at ${g}_A=0$. ](vector.eps "fig:") ![\[AxialVectorC\] The renormalized vector and axial charges of the positive- and the negative-parity nucleons are plotted as a function of the squared pion mass $m_\pi^2$. [**upper panel**]{}: The results of the vector charges. The solid line is drawn at ${g}_V=1$ for reference. [**lower panel**]{}: The results of the axial charges. The solid line is drawn at ${g}_A=1.26$ and the dashed line is drawn at ${g}_A=0$. ](axial.eps "fig:")

[**Results.**]{} We first take a stock of the vector charges $g_V^{0\pm}$ of the ground-state positive- and negative-parity nucleons as well as the axial charge $g_A^{0+}$ of the ground-state positive-parity nucleon, which are well known and can be the references. We show $g_V^{0\pm}$, the vector charges of the positive- and the negative-parity nucleons obtained with three hopping parameters $\kappa$=0.13