TY - JOUR
T1 - Covariant description of shape evolution and shape coexistence in neutron-rich nuclei at N≈60
AU - Xiang, J.
AU - Li, Z. P.
AU - Li, Z. X.
AU - Yao, J. M.
AU - Meng, J.
N1 - Funding Information:
J.M.Y. would like to thank Peter Ring and Yuan Tian for helpful discussions and acknowledge a postdoctoral fellowship from the F.R.S.–FNRS (Belgium). We also thank Paul-Henri Heenen for reading this manuscript. This work was partly supported by the Major State Basic Research Developing Program 2007 CB815000, the National Science Foundation of China under Grants No. 11105111, No. 11105110, No. 10947013 and No. 10975008, the Fundamental Research Funds for the Central Universities (XDJK2010B007 and XDJK2011B002), and the Southwest University Initial Research Foundation Grant to Doctor (SWU109011 and SWU110039).
PY - 2012/1/1
Y1 - 2012/1/1
N2 - The shape evolution and shape coexistence phenomena in neutron-rich nuclei at N≈ 60, including Kr, Sr, Zr, and Mo isotopes, are studied in the covariant density functional theory (DFT) with the new parameter set PC-PK1. Pairing correlations are treated using the BCS approximation with a separable pairing force. Sharp rising in the charge radii of Sr and Zr isotopes at N= 60 is observed and shown to be related to the rapid changing in nuclear shapes. The shape evolution is moderate in neighboring Kr and Mo isotopes. Similar as the results of previous Hartree-Fock-Bogoliubov (HFB) calculations with the Gogny force, triaxiality is observed in Mo isotopes and shown to be essential to reproduce quantitatively the corresponding charge radii. In addition, the coexistence of prolate and oblate shapes is found in both Sr98 and Zr100. The observed oblate and prolate minima are related to the low single-particle energy level density around the Fermi surfaces of neutron and proton respectively. Furthermore, the 5-dimensional (5D) collective Hamiltonian determined by the calculations of the PC-PK1 energy functional is solved for Sr98 and Zr100. The resultant excitation energy of 02+ state and E0 transition strength Ρ2(E0;02+→01+) are in rather good agreement with the data. It is found that the lower barrier height separating the two competing minima along the γ deformation in Zr100 gives rise to the larger Ρ2(E0;02+→01+) than that in Sr98.
AB - The shape evolution and shape coexistence phenomena in neutron-rich nuclei at N≈ 60, including Kr, Sr, Zr, and Mo isotopes, are studied in the covariant density functional theory (DFT) with the new parameter set PC-PK1. Pairing correlations are treated using the BCS approximation with a separable pairing force. Sharp rising in the charge radii of Sr and Zr isotopes at N= 60 is observed and shown to be related to the rapid changing in nuclear shapes. The shape evolution is moderate in neighboring Kr and Mo isotopes. Similar as the results of previous Hartree-Fock-Bogoliubov (HFB) calculations with the Gogny force, triaxiality is observed in Mo isotopes and shown to be essential to reproduce quantitatively the corresponding charge radii. In addition, the coexistence of prolate and oblate shapes is found in both Sr98 and Zr100. The observed oblate and prolate minima are related to the low single-particle energy level density around the Fermi surfaces of neutron and proton respectively. Furthermore, the 5-dimensional (5D) collective Hamiltonian determined by the calculations of the PC-PK1 energy functional is solved for Sr98 and Zr100. The resultant excitation energy of 02+ state and E0 transition strength Ρ2(E0;02+→01+) are in rather good agreement with the data. It is found that the lower barrier height separating the two competing minima along the γ deformation in Zr100 gives rise to the larger Ρ2(E0;02+→01+) than that in Sr98.
KW - Charge radii
KW - Covariant density functional
KW - Neutron-rich Kr, Sr, Zr, Mo isotopes
KW - Shape evolution and shape coexistence
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U2 - 10.1016/j.nuclphysa.2011.10.002
DO - 10.1016/j.nuclphysa.2011.10.002
M3 - Article
AN - SCOPUS:83955164229
VL - 873
SP - 1
EP - 16
JO - Nuclear Physics A
JF - Nuclear Physics A
SN - 0375-9474
ER -