English

Separable character of ab initio No-Core Shell Model one-body densities

Nuclear Theory 2026-03-13 v2

Abstract

Motivated by recent findings on the separability of optical potentials that are derived from folding off-shell densities with off-shell nucleon-nucleon amplitudes, we study the off-shell character of one-body density matrices created within the No-Core Shell Model (NCSM). Concentrating on nuclei with a 0+^+ ground state from 4^4He through 48^{48}Ca, we investigate the off-shell character of their one-body density matrices in momentum space when using the momentum transfer and the average momentum as variables. A singular value decomposition of the one-body density matrices reveals that they can be characterized by only very few terms, depending on the mass number of the nucleus. These findings are independent of the nucleon-nucleon interactions employed, as well as from computational specifics as grid spacing and size of the model space.

Keywords

Cite

@article{arxiv.2508.09890,
  title  = {Separable character of ab initio No-Core Shell Model one-body densities},
  author = {J. Foy and Ch. Elster and P. Maris and S. P. Weppner and S. K. Bogner},
  journal= {arXiv preprint arXiv:2508.09890},
  year   = {2026}
}

Comments

14 pages, 11 figures

R2 v1 2026-07-01T04:48:19.207Z