A＝20附近丰中子和丰质子核分离能的壳模型计算

摘要

使用原子核壳模型，研究 A＝20附近丰中子和丰质子核的分离能及滴线性质。在丰中子区，采用新的有效哈密顿量YSOX，此哈密顿量考虑了（2-3）核子的激发态，在此基础上研究 C、N 和 O 丰中子同位素的单双中子分离能。在丰质子区，通常的有效哈密顿量如 USD 系列没有考虑质子位于1s1／2轨道时的弱束缚效应，考虑此弱束缚效应修正哈密顿量，并用其研究18 Ne、19 Na、20 Mg、21 Al 和22 Si 等丰质子核的单双质子分离能。这些修正的哈密顿量对丰中子和丰质子核的分离能及滴线性质的描述比之前的哈密顿量有了显著的改善，正确地描述了已观测到的滴线性质，说明在研究滴线性质时弱束缚效应和多核子激发态的重要性。%The nuclear shell model is used to study the separation energies and the drip line properties in neutron and proton rich nuclei around A=20.In neutron rich region,the new effective Hamiltonian YSOX is used by considering the excitation of (2-3) nucleons.The one and two neutron separation energies of C,N,and O neutron rich isotopes are investigated based on this Ham-iltonian.In proton rich region,the weakly bound proton 1s1/2 orbit is not considered in normal Hamiltonians,such as USD fami-lies.After considering the modification of single particle energies and the two body matrix elements,the modified USD families are used to study the one and two proton separation energies of 18 Ne,19 Na,20 Mg,21 Al,and 22 Si.These modified Hamiltonians improve the descriptions of separation energies of neutron and proton rich nuclei comparing with the existing Hamiltonians.The drip line properties are significantly improved,which indicates the importance of the weakly bound effect and the excitations of multi nucleons.