Dipole responses in Nd and Sm isotopes with shape transitions
Dipole responses in Nd and Sm isotopes with shape transitions
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DOI：
10.1103/physrevc.83.021304
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发表时间：
2010-08
影响因子：
3.1
通讯作者：
Kenichi Yoshida;T. Nakatsukasa
中科院分区：
文献类型：
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作者：
Kenichi Yoshida;T. Nakatsukasa
利用Skyrme能量密度泛函，采用基于harree - fock - bogoliubov基态（HFB+QRPA）的准粒子-随机相位近似，系统地研究了Nd和Sm同位素从球形到变形均匀核的光吸收截面。随着中子数的增加，基态的变形逐渐发生，导致了形状相变的特征。计算结果很好地再现了截面上双峰结构展宽和出现的同位素依赖关系，无需任何可调参数。我们还发现变形对低能偶极子强度起着重要的作用。$E1$的强度是分散的，能量相当低。总$E1$强度高达10 MeV，提高了五倍或更多。
Photoabsorption cross sections of Nd and Sm isotopes from spherical to deformed even nuclei are systematically investigated by means of the quasiparticle-random-phase approximation based on the Hartree-Fock-Bogoliubov ground states (HFB+QRPA) using the Skyrme energy density functional. The gradual onset of deformation in the ground states as increasing the neutron number leads to characteristic features of the shape phase transition. The calculation well reproduce the isotopic dependence of broadening and emergence of a double-peak structure in the cross sections without any adjustable parameter. We also find that the deformation plays a significant role for low-energy dipole strengths. The $E1$ strengths are fragmented and considerably lowered in energy. The summed $E1$ strength up to 10 MeV is enhanced by a factor of five or more.