Rafelski, J; Müller, B, *Vector coupling and bound states of fermions in three space dimensions*,
Physical Review D, vol. 14 no. 12
(1976),
pp. 3532-3535 [doi] .
**Abstract:**

*The behavior of fermions interacting via vector gluons in the strong-coupling limit is investigated. A suitable coupling between the Dirac and the vector-gluon field gives rise to bound-state solutions. The coherent field approximation is employed to find the bound-state masses, which are further discussed by analytical and numerical methods and are found to be positive-definite in the example considered numerically. © 1976 The American Physical Society.*