Renormalized interactions with a realistic single particle basis

TL;DR

This paper presents a method to modify effective nuclear interactions for neutron-rich isotopes by accounting for the weakly bound nature of single particle orbits, improving agreement with experimental data.

Contribution

It introduces a procedure using realistic wavefunctions and NN interactions to justify modifications to effective interactions in shell model calculations.

Findings

Reduced matrix elements for loosely bound orbits

More condensed level spacing in shell model results

Improved agreement with experimental data for 36Si and 38Si

Abstract

Neutron-rich isotopes in the sdpf space with Z < 15 require modifications to derived effective interactions to agree with experimental data away from stability. A quantitative justification is given for these modifications due to the weakly bound nature of model space orbits via a procedure using realistic radial wavefunctions and realistic NN interactions. The long tail of the radial wavefunction for loosely bound single particle orbits causes a reduction in the size of matrix elements involving those orbits, most notably for pairing matrix elements, resulting in a more condensed level spacing in shell model calculations. Example calculations are shown for 36Si and 38Si.