where $$\begin{aligned}
Z_2 &=& 1 + \frac{g^2}{16\pi^2} C_F \left[ \log (\lambda a)^2
 + \Sigma_1\right],
\\
V_\Gamma &=& 1 + \frac{g^2}{16\pi^2} \left[ -\delta_\Gamma \log (\lambda a)^2
+ v_\Gamma \right],\end{aligned}$$ $$\begin{aligned}
v_+ &=&\frac{16\pi^2(N-1)}{N}\left[ <T> (N+1)+<<A_{VA}>>(N+2)-<<A_{SP}>>
\right] +\delta_+ \log \pi^2,
 \\
v_- &=&\frac{16\pi^2(N+1)}{N}\left[ <T> (N-1)+<<A_{VA}>>(N-2)+<<A_{SP}>>
\right] +\delta_- \log \pi^2,
 \\
v_1 &=&\frac{16\pi^2}{N}\left[ <T> (N^2-1)+<<A_{VA}>>N^2-<<A_{SP}>>
\right] +\delta_1 \log \pi^2,
 \\
v_2 &=&\frac{16\pi^2(N^2-1)}{N}\left[ <T> + <<A_{SP}>>
\right] +\delta_2 \log \pi^2 \end{aligned}$$ with $$\delta_\Gamma =
\left\{
\begin{array}{ll}
\displaystyle \frac{(N-1)(N-2)}{N} & \qquad \Gamma = + \\
& \\
\displaystyle \frac{(N+1)(N+2)}{N} & \qquad \Gamma = - \\
& \\
\displaystyle \frac{(N+2)(N-2)}{N} & \qquad \Gamma = 1 \\
& \\
\displaystyle \frac{4(N+1)(N-1)}{N} & \qquad \Gamma = 2 
\end{array}
\right.$$ The infrared singularity of $< A_X>$ is subtracted as $$<< A_X >> = \int_{-\pi}^{\pi}\frac{d^4k}{(2\pi)^4} 
\left[K(k) A_X(k) - c_X \frac{1}{(k^2)^2}\theta(\pi^2-k^2)\right]$$ with $c_{SP}=4$ and $c_{VA}=1$.

Numerical values of $v_\Gamma$ are evaluated by two independent methods. In one method the momentum integration is performed by a mode sum for a periodic box of a size $L^4$ after transforming the momentum variable through $k_\mu = q_\mu -\sin q_\mu$. We employ the size $L=64$ for integrals. In the other method the momentum integration is carried out by the the Monte Carlo integration routine VEGAS, using 