Influence of quadrupole deformation and continuum effects on the exotic properties of 15,17,19B with the complex momentum representation method postprint

Abstract: The properties of exotic nuclei are the focus of the present research. Two-neutron halo structures of neutron-rich ^17,19B were experimentally confirmed. We studied the formation mechanism of halo phenomena in ^{17, 19}B using the complex momentum representation method applied to deformation and continuum coupling. By examining the evolution of the weakly bound and resonant levels near the Fermi surface, s–d orbital reversals and certain prolate deformations were observed. In addition, by analyzing the evolution of the occupation probabilities and density distributions occupied by valence neutrons, we found that the ground state of ¹⁵B did not exhibit a halo, and the ground states of ¹⁷B and ¹⁹B exhibited halos at 0.6≤β₂≤0.7 and 0.3≤β2≤0.7, respectively. The low-l components in the valence levels that are weakly bound or embedded in the continuous spectrum lead to halo formation.