k^{\frac{1}{2}})(C_{+}^2 - C_{-}^2))\nonumber\\
&&(\bar b_i\gamma_{\alpha}(1
- \gamma_5)b_i)(\bar c_j\gamma^{\alpha}(1 - \gamma_5)c_j) + \label{20}\\
&& k^{\frac{1}{2}}(C_{+}^2 - C_{-}^2)(\bar b_i\gamma_{\alpha}(1 - \gamma_5)b_j)
(\bar c_j\gamma^{\alpha}(1 - \gamma_5)c_i)],\nonumber\\
{\cal T}_{WS,bu} &=&
\frac{G_F^2|V_{cb}|^2}{4\pi}m_b^2(1+\frac{m_u}{m_b})^2(1-z_{+})^2[(C_{+}^2 +
C_{-}^2 +
 \frac{1}{3}(1 - k^{\frac{1}{2}})(C_{+}^2 - C_{-}^2))\nonumber\\
&&(\bar b_i\gamma_{\alpha}(1
- \gamma_5)b_i)(\bar u_j\gamma^{\alpha}(1 - \gamma_5)u_j) + \label{21}\\
&& k^{\frac{1}{2}}(C_{+}^2 - C_{-}^2)(\bar b_i\gamma_{\alpha}(1 - \gamma_5)b_j)
(\bar u_j\gamma^{\alpha}(1 - \gamma_5)u_i)],\nonumber\\
{\cal T}_{WS,cd} &=&
\frac{G_F^2}{4\pi}m_c^2(1+\frac{m_d}{m_c})^2(1-z_{+})^2[(C_{+}^2 + C_{-}^2 +
 \frac{1}{3}(1 - k^{\frac{1}{2}})(C_{+}^2 - C_{-}^2))\nonumber\\
&&(\bar c_i\gamma_{\alpha}(1
- \gamma_5)c_i)(\bar d_j\gamma^{\alpha}(1 - \gamma_5)d_j) + \label{22}\\
&& k^{\frac{1}{2}}(C_{+}^2 - C_{-}^2)(\bar c_i\gamma_{\alpha}(1 - \gamma_5)c_j)
(\bar d_j\gamma^{\alpha}(1 - \gamma_5)d_i)],\nonumber\end{aligned}$$ $$\begin{aligned}
{\cal T}_{PI,d\bar u}^b &=& {\cal T}_{PI,s\bar c}^b~(z_{-}\to 0)\\
{\cal T}_{PI,e\bar\nu_e}^b &=& {\cal T}_{PI,\mu\bar\nu_{\mu}}^b =
{\cal T}_{PI,\tau\bar\nu_{\tau}}^b~(z_{\tau}\to 0),\\
{\cal T}_{PI,\nu_e\bar e}^c &=& {\cal T}_{PI,\nu_{\mu}\bar\mu}^c =
{\cal T}_{PI,\nu_{\tau}\bar\tau}^c~(z_{\tau}\to 0),\end{aligned}$$ where the following notation has been used: $$\begin{aligned}
\mbox{in Eq.}~(\ref{16})&& z_{-} = \frac{m_c^2}{(m_b-m_c)^2},\quad
k = \frac{\alpha_s(\mu)}{\alpha_s(m_b-m_c)},\nonumber\\ \mbox{in
Eq.}~(\ref{17})&& z_{\tau} =
\frac{m_{\tau}^2}{(m_b-m_c)^2},\nonumber\\ \mbox{in
Eq.}~(\ref{18})&& z_{-} = \frac{m_c^2}{(m_b-m_d)^2},\quad k =
\frac{\alpha_s(\mu)}{\alpha_s(m_b-m_d)},\nonumber\\ \mbox{in
Eq.}~(\ref{181})&& z_{-} = \frac{m_c^2}{(m_b-m_s)^2},\quad k =
\frac{\alpha_s(\mu)}{\alpha_s(m_b-m_s)},\nonumber\\ \mbox{in
Eq.}~(\ref{19})&& z_{-} = \frac{m_s^2}{(m_c-m_u)^2},\quad k =
\frac{\alpha_s(\mu)}{\alpha_s(m_c-m_u)},\nonumber\\ \mbox{in
Eq.}~(\ref{191})&&  k =
\frac{\alpha_s(\mu)}{\alpha_s(m_c-m_s)},\nonumber\\ \mbox{in
Eq.}~(\ref{192})&& z_{\tau} =
\frac{m_{\tau}^2}{(m_c-m_s)^2},\nonumber\\ \mbox{in
Eq.}~(\ref{20})&& z_{+} = \frac{m_c^2}{(m_b+m_c)^2},\quad k =
\frac{\alpha_s(\mu)}{\alpha_s(m_b+m_c)},\nonumber\\ \mbox{in
Eq.}~(\ref{21})&& z_{+} = \frac{m_c^2}{(m_b+m_u)^2},\quad k =
\frac{\alpha_s(\mu)}{\alpha_s(m_b+m_u)},\nonumber\\ \mbox{in
Eq.}~(\ref{22})&& z_{+} = \frac{m_s^2}{(m_c+m_d)^2},\quad k =
\frac{\alpha_s(\mu)}{\alpha_s(m_c+m_d)}.\nonumber\end{aligned}$$ In the evolution of coefficients $C_{+}$ 