Anharmonicity of multi-octupole-phonon excitations in Pb-208: Analysis with multireference covariant density functional theory and subbarrier fusion of O-16+Pb-208

作者：Yao, J. M.^*; Hagino, K.

来源：PHYSICAL REVIEW C, 2016, 94(1): 011303.

DOI：10.1103/PhysRevC.94.011303

• HEAVY-ION FUSION
• NUCLEI
• STATES
• FRAGMENTATION
• VIBRATIONS
• BARRIERS

We discuss anharmonicity of the multi-octupole-phonon states in Pb-208 based on a covariant density functional theory by fully taking into account the interplay between the quadrupole and the octupole degrees of freedom. Our results indicate the existence of a large anharmonicity in the transition strengths, even though the excitation energies are similar to those in the harmonic limit. We also show that the quadrupole-shape fluctuation significantly enhances the fragmentation of the two-octupole-phonon states in Pb-208. Using those transition strengths as inputs to coupled-channels calculations, we then discuss the fusion reaction of O-16 + Pb-208 at energies around the Coulomb barrier. We show that the anharmonicity of the octupole vibrational excitation considerably improves previous coupled-channels calculations in the harmonic-oscillator limit, significantly reducing the height of the main peak in the fusion barrier distribution.

• 出版日期2016-7-18
• 单位西南大学; 中国科学院国家天文台