Subbarrier heavy ion fusion enhanced by nucleon transfer

We discuss a model for the description of subbarrier fusion of heavy ions which takes into account the coupling to the low-energy surface vibrational states and to the few-nucleon transfer with arbitrary reaction Q-value. The fusion reactions Si-28,Si-30+Ni-58,Ni-62,Ni-64, Ca-40+Zr-90,Zr-96, S-28+Mo-94,Mo-100, Ni-58+Ni-64, O-16,O-18,O-20,O-22,O-24+Ni-58 and Si-28+Sn-124,Sn-126,Sn-128,Sn-130,Sn-132 are analyzed in detail. The model describes rather well the experimental fusion cross section and mean angular momentum for reactions between nuclei near the beta-stability line. It is shows that these quantities are significantly enhanced by few-nucleon transfer with large positive Q-value. A shape independent parameterization of the heavy ion potential at distances smaller then the touching point is proposed.