Weak response of cold symmetric nuclear matter at three-body cluster level

The Fermi and Gamow-Teller responses of cold symmetric nuclear matter have been studied within a unified dynamical model, suitable to account for both short- and long-range correlation effects. The formalism of correlated basis functions has been used to construct two-body effective interactions and one-body effective weak operators. The inclusion of the three-body cluster term allowed for the incorporation in our scheme of a realistic model of three-nucleon interactions, referred to as Urbana IX (UIX). Moreover, our results show that the sizable dependence of the effective weak operator on the details of the correlation functions is in fact unphysical, and disappears once the three-body cluster term is taken into account.