Energies of the single-particle proton 1 and 2 states in the Ni isotopes

Ni同位体における1及び2単一陽子状態のエネルギー

Bespalova, O. V.*; Boboshin, I. N.*; Varlamov, V. V.*; Ermakova, T. A.*; Ishkhanov, B. S.*; Komarov, S. Yu.*; 小浦 寛之   ; Romanovskii, E. A.*; Spasskaya, T. I.*

Bespalova, O. V.*; Boboshin, I. N.*; Varlamov, V. V.*; Ermakova, T. A.*; Ishkhanov, B. S.*; Komarov, S. Yu.*; Koura, Hiroyuki; Romanovskii, E. A.*; Spasskaya, T. I.*

ニッケル同位体Niの単一陽子準位のうち、閉殻構造を形成するのに特に重要となる1軌道及び2軌道の系統性について調べた。分散光学模型を用いて計算すると、中性子過剰核側では1軌道間の間隔は大きくなり(NiからNiで約4MeV程度)、また2軌道間の間隔はほとんど変化しないかわずかに減少する傾向となる。典型的な一体場単一粒子準位計算であるWoods-Saxon型及びその修正ポテンシャルでは1f軌道間隔が広がるような変化はほとんど見られない。分散光学模型はHartree-Fockな静的部分と、分散的な動的部分から成り、後者の効果によりこのような性質が表れたと考えられる。

Single-particle energies corresponding to the maximum value of the spectroscopic factor were obtained for the proton states near the Fermi energy in the Ni nuclei by the joint evaluation of the data on the stripping and pickup reactions on the same nucleus. These results are compared with the center-of-mass energies of the single-particle state fragment distributions obtained by the same method and with the single-particle energies calculated with the Woods-Saxon-like potential and with the dispersive optical model potential. For 2 states (the first unoccupied states), Results of the Woods-Saxon-like potential are in excellent agreement with the energies of maximum (practically the same), for 1, 1 and for 2 states the agreement within 1 - 1.5 MeV was achieved. Sufficient difference between centers of mass and maximums was obtained for 1 and 2 states, which may be connected with the fragmentation effect.