Recently measured high precision data of fusion excitation function have enabled a detailed study on the effects of nuclear collective excitations on fusion reactions. Using such highly accurate data of the $^{ 16}$O + $^{ 144,148}$Sm reactions, we discuss the anharmonic properties of collective phonon excitations in $^{ 144,148}$Sm nuclei. It is shown that subbarrier fusion reactions are strongly affected by the anharmonic effects and thus offer an alternative method to extract the static quadrupole moments of phonon states in a spherical nucleus.
Categories: nucl-th