THE 3-NUCLEON BOUND-STATE WITH REALISTIC SOFT-CORE AND HARD-CORE POTENTIALS

The wave function of the three-nucleon bound state is decomposed in the LS coupling scheme and the radial amplitudes of all the channels considered are expanded on a set of correlated basis functions. Two different types of correlated expansions are investigated, namely the pair (PHH) and the Jastrow (CHH) correlated hyperspherical-harmonic expansions. The correlation factor includes only one pair-correlation function per channel in the PHH case, whilst it is a product of three pair-correlation functions per channel in the CHH case. The optimal dependence on the hyperradius is determined by means of a variational technique. For the Argonne AV14 potential the results given by the PHH expansion are in very close agreement with those of Kameyana et al. The CHH expansion allows for treating hard-core interactions too, and the results obtained for the Hamada-Johnston potential noticeably improve those obtained with other methods.