6Li in a Three-Body Model with Realistic Forces: Separable vs. Non-separable Approach

Linda Hlophe, NSCL/FRIN
Tuesday, Sep 26, 11:00 AM - Theory Seminar
1200 FRIB Laboratory

Abstract:  Faddeev equations in momentum space have a long tradition of utilizing separable interactions in order to arrive at sets of coupled integral equations in one variable. However, it needs to be demonstrated that their solution based on separable interactions agrees exactly with solutions based on non-separable forces. I will discuss calculations of the 6 Li ground state via momentum space Faddeev equations using the CD-Bonn neutron-proton force and a Woods- Saxon type neutron(proton)- 4 He force. For the latter the Pauli-forbidden s-wave bound state is projected out. Two methods for evaluating the 6 Li three-body ground state are considered. First, we solve the bound state Faddeev equations directly using the afore-mentioned two-body potentials. In the second approach, the interactions in the two-body subsystems are represented by separable interactions derived in the Ernst-Shakin-Thaler (EST) framework. We find that by utilizing the full parameter space of the EST separable expansion, one can attain a precision of upto four significant figures in three-body binding energy. It is also shown that the three-body binding energy computed in this manner agrees fully with the one obtained directly within the stated numerical precision. The momentum distributions computed in both approaches also fully agree with each other.