A Universal Damping Mechanism of Quantum Vibrations in Deep Sub-Barrier Fusion Reactions

Abstract

We demonstrate the damping of quantum octupole vibrations near the touching point when two colliding nuclei approach each other in the mass-asymmetric ${}^{208}$Pb + ${}^{16}$O system, for which the strong fusion hindrance was clearly observed. We, for the first time, apply the random-phase approximation method to the heavy-mass asymmetric di-nuclear system to calculate the transition strength $B$(E3) as a function of the center-of-mass distance. The obtained $B$(E3) strengths are substantially damped near the touching point, because the single-particle wave functions of the two nuclei strongly mix with each other and a neck is formed. The energy-weighted sums of $B$(E3) are also strongly correlated with the damping factor which is phenomenologically introduced in the standard coupled-channel calculations to reproduce the fusion hindrance. This strongly indicates that the damping of the quantum vibrations universally occurs in the deep sub-barrier fusion reactions.

4 pages, 4 figures

References in corpus (9)

• Subbarrier fusion reactions and many-particle quantum tunneling
• Hindrance of heavy-ion fusion due to nuclear incompressibility
• Signature of Shallow Potentials in Deep Sub-barrier Fusion Reactions
• Heavy-ion interaction potential deduced from density-constrained TDHF calculation
• Systematics of threshold incident energy for deep sub-barrier fusion hindrance
• Hindrance of ^{16}O+^{208}Pb fusion at extreme sub-barrier energies
• Microscopic study of Ca$+$Ca fusion
• Existence of One-Body Barrier Revealed in Deep Sub-Barrier Fusion
• Density-constrained time-dependent Hartree-Fock calculation of ${}^{16}$O+${}^{208}$Pb fusion cross sections

Cited by in corpus (6)

• Recent experimental results in sub- and near-barrier heavy ion fusion reactions
• Systematic investigations of deep sub-barrier fusion reactions using an adiabatic approach
• Quantum tunneling with friction
• Origin of a maximum of astrophysical $S$ factor in heavy-ion fusion reactions at deep subbarrier energies
• Effect of Pauli repulsion and transfer on fusion
• New and efficient method for solving the eigenvalue problem for the two-center shell model with finite-depth potentials