Anharmonicity of multi-octupole-phonon excitations in ${}^{208}$Pb: analysis with multi-reference covariant density functional theory and subbarrier fusion of ${}^{16}$O+${}^{208}$Pb

Abstract

We discuss anharmonicity of the multi-octupole-phonon states in ${}^{208}$Pb 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 ${}^{208}$Pb. Using those transition strengths as inputs to coupled channels calculations, we then discuss the fusion reaction of ${}^{16}$O+${}^{208}$Pb 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.

5 pages with 4 figures, to be published in Phys. Rev. C as a Rapid Communication

References in corpus (6)

• New parametrization for the nuclear covariant energy density functional with point-coupling interaction
• Subbarrier fusion reactions and many-particle quantum tunneling
• A microscopic benchmark-study of triaxiality in low-lying states of 76Kr
• Hindrance of ^{16}O+^{208}Pb fusion at extreme sub-barrier energies
• Symmetry conserving configuration mixing method with cranked states
• An efficient method for computing the Thouless-Valatin inertia parameters

Cited by in corpus (5)

• How the Pauli exclusion principle affects fusion of atomic nuclei
• Recent experimental results in sub- and near-barrier heavy ion fusion reactions
• Spectroscopy of reflection-asymmetric nuclei with relativistic energy density functionals
• Microscopic core-quasiparticle coupling model for spectroscopy of odd-mass nuclei with octupole correlations
• Generator coordinate method for nuclear octupole excitations: status and perspectives