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تسجيل مستخدم جديدSub-barrier fusion of 32S+90,96Zr: semi-classical coupled-channels approach
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The fusion excitation functions have been measured with rather good accuracy for 32S+90Zr and 32S+96Zr near and below the Coulomb barrier. The sub-barrier cross sections for 32S+96Zr are much larger compared with 32S+90Zr. Semi-classical coupled-channels calculations including two-phonon excitations are capable to describe sub-barrier enhancement only for 32S+90Zr. The remaining disagreement for 32S+96Zr comes from the positive Q-value intermediate neutron transfers in this system. The comparison with 40Ca+96Zr suggests that couplings to the positive Q-value neutron transfer channels may play a role in the sub-barrier fusion enhancement. A rather simple model calculation taking neutron transfers into account is proposed to overcome the discrepancies of 32S+96Zr.
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A steeper fall of fusion excitation function, compared to the predictions of coupled-channels models, at energies below the lowest barrier between the reaction partners, is termed as deep sub-barrier fusion hindrance. This phenomenon has been observe
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