     B_{0} &=& - \frac{0  k_0^0 m^0}{000  k_0^0} -  \frac{0  k_0 m^0 \kappa^0}{00  k_0^0} + \frac{  k_0 m^0 \lambda}{0  k_0^0} + \frac{00 m^0 \kappa^0 \lambda}{000  k_0^0} -  \frac{ \lambda^0}{00  k_0^0} \nonumber \\ && 