The complex momentum representation approach and its application to low-lying resonances in 17O and 29,31F

Approaches for predicting low-lying resonances, uniformly treating bound, and resonant levels have been a long-standing goal in nuclear theory. Accordingly, we explored the viability of the complex momentum representation (CMR) approach coupled with new potentials. We focus on predicting the energy of the low-lying 2p(3/2) resonance in O-17, which is critical for s-process nucleosynthesis and missing in previous theoretical research. Using a Woods-Saxon potential based on the KoningDelaroche optical model and constrained by the experimental one-neutron separation energy, we successfully predicted the resonant energy of this level for the first time. Our predictions of the bound levels and 1d(3/2) resonance agree well with the measurement results. Additionally, we utilize this approach to study the near-threshold resonances that play a role when forming a two-neutron halo in( 29,31) F. We found that the CMR-based predictions of the bound-level energies and unbound 1f(7/2) level agree well with the results obtained using the scattering phase shift method. Subsequently, we successfully found a solution for the 2p(3/2) resonance with energy just above the threshold, which is decisive for halo formation.

Automated summary

In this study, the complex momentum representation (CMR) approach coupled with new potentials was used to successfully predict the resonant energy of the 2p(3/2) state in O-17 and to study near-threshold resonances in (29,31)F that contribute to halo formation.