Relativistic Equation for a Four-Nucleon System

The four-particle integral Faddeev–Yakubovsky equation is generalized to the relativistic case. The system of integral equations that was obtained in this way is solved by the iteration method, and the binding energy of the helium-4 nucleus and the amplitudes for its states are found. The rank-one separable Yamaguchi potential is used for the \(NN\) interaction potential. The calculations are performed only for states of zero orbital angular momentum—that is, for \(S\) states. The results of the calculations are compared with the results of nonrelativistic calculations and with experimental data.