$\mathrm{it}L=ī\Psi {\gamma }^{\mu }{\partial }_{\mu }\Psi -̄\Psi \Psi -q̄\Psi {\gamma }^0\Psi \Phi +1\mathrm{over}2\left({\partial }_{\mu }\Phi \right)\left({\partial }^{\mu }\Phi \right)$