Low-momentum nucleon-nucleon interaction and its application to the few-nucleon systems
Low-momentum nucleon-nucleon interactions are derived within the framework of a unitary-transformation theory, starting with realistic nucleon-nucleon interactions. A cutoff momentum Lambda is introduced to specify a border between the low- and high-momentum spaces. By the Faddeev-Yakubovsky calculations the low-momentum interactions are investigated with respect to the dependence of ground-state energies of 3H and 4He on the parameter Lambda. It is found that we need the momentum cutoff parameter Lambda 5 fm -1 in order to reproduce satisfactorily the exact values of the binding energies for 3H and 4He. The calculation with Lambda =2 fm -1 recommended by Bogner et al. leads to considerable overbinding at least for the few-nucleon systems.