Excitation of nuclear anharmonic vibrations in heavy-ion fusion reactions

Abstract

We discuss the effects of multi-phonon excitations on heavy-ion fusion reactions at energies near and below the Coulomb barrier, focusing especially on the role of anharmonicities. We carry out a systematic study of those effects on the excitation function of the fusion cross section and on the fusion barrier distribution, by using the vibrational limit of the interacting boson model. We also analyze the recently measured high-precision data of the ${}^{16}$O + ${}^{148}$Sm fusion reaction with this model and discuss the anharmonic properties of the quadrupole as well as the octupole vibrations in ${}^{148}$Sm. Negative and positive static quadrupole moments are deduced for the first 2${}^{+}$ and 3${}^{-}$ states in ${}^{148}$Sm, respectively. It is shown that the fusion barrier distribution strongly depends on the sign of the quadrupole moments, suggesting that subbarrier fusion reactions offer an alternative method to extract the static quadrupole moments of phonon states in spherical nuclei.

21 pages, 9 figures, Submitted to Physical Review C

References in corpus (6)

• Adiabatic quantum tunneling in heavy-ion sub-barrier fusion
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• Role of anharmonicities and non-linearities in heavy ion collisions. A microscopic approach
• Variational approach to anharmonic collective motion
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Cited by in corpus (10)

• Coupled-channels analysis of the ${}^{16}$O+${}^{208}$Pb fusion barrier distribution
• Coupled-channels calculations for nuclear reactions: from exotic nuclei to superheavy elements
• Sensitivity to multi-phonon excitations in heavy-ion fusion reactions
• 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
• Coupled-channels analyses for large-angle quasi-elastic scattering in massive systems
• Role of non-collective excitations in heavy-ion fusion reactions and quasi-elastic scattering around the Coulomb barrier
• Anharmonic collective excitation in a solvable model
• Effects of finite width of excited states on heavy-ion sub-barrier fusion reactions
• Systematic study of the effect of individual rotational energy levels on the fusion cross-section of \texorpdfstring{${}^{16}O$}--based reactions of range $480\le Z_P{Z}_T\le 592$
• Excitation of multiple giant dipole resonances: from spherical to deformed nuclei