English

Chiral NNLO$_{\text{sat}}$ descriptions of nuclear multipole resonances within the random phase approximation

Nuclear Theory 2018-05-09 v1

Abstract

We study nuclear multipole resonances in the framework of the random phase approximation using the chiral potential NNLOsat_{\text{sat}}. This potential includes two- and three-body terms that has been simultaneously optimized to low-energy nucleon-nucleon scattering data and selected nuclear structure data. Our main foci have been the isoscalar monopole, isovector dipole, and isoscalar quadrupole resonances of the closed-shell nuclei, 4^4He, 16,22,24^{16,22,24}O, and 40,48^{40,48}Ca. These resonance modes have been widely observed in experiment. In addition, we use a renormalized chiral potential Vlow-kV_{\text{low-}k}, based on the N3^3LO two-body potential by Entem and Machleidt [Phys. Rev. \textbf{C68}, 041001 (2011)]. This introduces a dependency on the cutoff parameter used in the normalization procedure as reported in previous works by other groups. While NNLOsat_{\text{sat}} can reasonably reproduce observed multipole resonances, it is not possible to find a single cutoff parameter for the Vlow-kV_{\text{low-}k} potential that simultaneously describe the different types of resonance modes. The sensitivity to the cutoff parameter can be explained by missing induced three-body forces in the calculations. Our results for neutron-rich 22,24^{22,24}O show a mixing nature of isoscalar and isovector resonances in the dipole channel at low energies. We predict that 22^{22}O and 24^{24}O have low-energy isoscalar quadrupole resonances at energies lower than 5 MeV.

Keywords

Cite

@article{arxiv.1801.04454,
  title  = {Chiral NNLO$_{\text{sat}}$ descriptions of nuclear multipole resonances within the random phase approximation},
  author = {Q. Wu and B. S. Hu and F. R. Xu and Y. Z. Ma and S. J. Dai and Z. H. Sun and G. R. Jansen},
  journal= {arXiv preprint arXiv:1801.04454},
  year   = {2018}
}

Comments

25 pages, 8 figures