Application of the method of integral equations for calculating the vertex constants for an α-particle

The vertex constants Gsub(αTN)2 and Gsub(αdd)2 for the virtual decays α→t(tau)+p(n) and α→d+d are calculated by solving the Faddeev-Yakubovsky equations for four nucleons. A spin-dependent separable potential with the Hulthen form factor is used as the NN interaction. The resonant Hilbert-Schmidt expansion is applied to solve the integral equations. The values obtained Gsub(αTN)2=17.9+-1.7 fm and Gsub(αdd)2=18.1+-1.3 fm are compared with the phenomenological values extracted from data on nuclear reactions. (Auth.)