The Instantaneous Bethe-Salpeter Equation and Its Analog: the Breit-like Equation

Chao-Hsi Chang, Jiao-Kai Chen

We take (${\mu }^{\pm }{e}^{\mp }$) systems and consider the states with quantum number $J^P=0^{-}$ as examples, to explore the different contents of the instantaneous Bethe-Salpeter (BS) equati…