Chiral NNLOsat descriptions of nuclear multipole resonances within the random-phase approximation

Q. Wu, B. S. Hu, F. R. Xu, Y. Z. Ma, S. J. Dai, Z. H. Sun, G. R. Jansen
2018 Physical Review C  
We study nuclear multipole resonances in the framework of the random phase approximation using the chiral potential NNLO_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, ^4He, ^16,22,24O, and ^40,48Ca. These resonance modes have been widely
more » ... bserved in experiment. In addition, we use a renormalized chiral potential V_low-k, based on the N^3LO two-body potential by Entem and Machleidt [Phys. Rev. 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 NNLO_sat can reasonably reproduce observed multipole resonances, it is not possible to find a single cutoff parameter for the V_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 ^22,24O show a mixing nature of isoscalar and isovector resonances in the dipole channel at low energies. We predict that ^22O and ^24O have low-energy isoscalar quadrupole resonances at energies lower than 5 MeV.
doi:10.1103/physrevc.97.054306 fatcat:hknfmnpmzja77n56iwpi26ihhu