The binding energy of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ is calculated within the framework of the Yakubovsky equations for the Reid soft-core potential. Use is made of separable expansions of the subamplitudes. With neglect of the Coulomb effect and the non-$s$-wave parts of the two-nucleon $t$ matrix, the binding is found to be 19.5 MeV. With use of the solutions of the integral equations the elastic charge form factor is calculated. In addition to the underbinding of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ it is found that the secondary maximum in the form factor is much too low as compared to experiment.

• Received 23 February 1978

DOI:https://doi.org/10.1103/PhysRevLett.40.1239