master
{\it L}=i\bar{\Psi}{\gamma}^{\mu}{\partial}_{\mu}{\Psi}-\bar{\Psi}{\Psi}-q\bar% {\Psi}{\gamma}^{0}{\Psi}\Phi+{1\over 2}({\partial}_{\mu}\Phi)({\partial}^{\mu}% \Phi)