Nuclear structure study with two- and three-nucleon contact interactions derived within low-energy EFT

TL;DR

This paper develops a low-energy effective field theory-based nuclear Hamiltonian with contact interactions, fitted to experimental data, and tests its ability to reproduce properties of open-shell nuclei through shell-model calculations.

Contribution

It derives and validates a nuclear Hamiltonian with contact interactions within low-energy EFT, applied to shell-model studies of open-shell nuclei, comparing with chiral perturbation theory results.

Findings

Successfully reproduces key features of open-shell nuclei

Effective Hamiltonians align well with experimental data

Provides a simpler alternative to pion-exchange based models

Abstract

We present the results of the application of a nuclear potential consisting of two- and three-nucleon contact interactions in nuclear structure investigations. The nuclear Hamiltonian has been derived for a very low-energy regime within the framework of the effective field theory, its low-energy constants have been fitted to a few low-energy nucleon-nucleon experimental observables and the deuteron and 3H binding energies. Our goal is to validate the ability of this Hamiltonian to reproduce some important features of open-shell nuclei, and to this end we derive effective shell-model Hamiltonians for nuclei in the p- and sd-shell mass regions. The results of shell-model calculations with these effective Hamiltonians are then compared with experiment, and also with those obtained with a nuclear Hamiltonian derived within chiral perturbation theory, that includes also terms with one- and two-pion exchanges.