Near-barrier fusion of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow/><mml:mrow><mml:mn>36</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mi mathvariant="normal">S</mml:mi><mml:mrow><mml:msup><mml:mrow><mml:mo>+</mml:mo></mml:mrow><mml:mrow><mml:mn>9</mml:mn><mml:mn>0</mml:mn><mml:mo>,</mml:mo><mml:mn>9</mml:mn><mml:mn>6</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mi mathvariant="normal">Zr</mml:mi><mml:mo>:</mml:mo></mml:math>The effect of the strong octupole vibration of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow/><mml:mrow><mml:mn>96</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mi mathvariant="normal">Zr</mml:mi></mml:math>

Fusion-evaporation cross sections have been measured for ${}^{36}\mathrm{S}{+}^{90,96}\mathrm{Zr}$ to high accuracy near the Coulomb barrier. The sub-barrier cross sections for ${}^{36}\mathrm{S}{+}^{96}\mathrm{Zr}$ are much larger compared to ${}^{36}\mathrm{S}{+}^{90}\mathrm{Zr}.$ The extracted fusion barrier distributions have different shapes, with essentially one peak for ${}^{36}\mathrm{S}{+}^{90}\mathrm{Zr},$ and a wider and more complex structure for ${}^{36}\mathrm{S}{+}^{96}\mathrm{Zr}.$ Coupled-channels calculations explain the larger sub-barrier enhancement for ${}^{36}\mathrm{S}{+}^{96}\mathrm{Zr}$ as due mainly to the strong octupole vibration in ${}^{96}\mathrm{Zr}.$ However, the calculations do not reproduce well the barrier distribution for this system. The comparison with ${}^{40}\mathrm{Ca}{+}^{90,96}\mathrm{Zr}$ suggests that couplings to nucleon transfer channels may play a role in the large enhancement of sub-barrier fusion for ${}^{40}\mathrm{Ca}{+}^{96}\mathrm{Zr}.$

Перевод пока недоступен