ON THE BOUND STATES IN A NONLINEAR QUANTUM FIELD THEORY OF A SPINOR FIELD WITH HIGHER DERIVATIVES

We consider a model with higher derivatives for a spinor field with Fermi-type self-interaction. The problem of two-particle bound states is investigated with the help of the Bethe–Salpeter equation. It is shown that a scalar bound state exists when the coupling constant has a very finely tuned magnitude.