Investigation of dynamic effects on fusion cross sections for reactions $$^{16,18}$$ 16 , 18 O + $$^{112,116,118,124}$$ 112 , 116 , 118 , 124 Sn

The dynamic effects on fusion cross sections for $$^{16,18}$$ O + $$^{112,116,118,124}$$ Sn are investigated by using the universal fusion function prescription and the empirical coupled-channel (ECC) model. An examination of the reduced fusion excitation functions shows that the sub-barrier fusion cross sections of $$^{18}$$ O + $$^{112,116}$$ Sn exhibit an extra enhancement as compared to those of $$^{16}$$ O + $$^{112,116}$$ Sn. Then the enhancements of fusion cross sections due to couplings to inelastic excitation channels and positive Q-value neutron transfer channel are evaluated separately by using the ECC model. The results show that the data of $$^{16,18}$$ O + $$^{112,116,118,124}$$ Sn are described well by the ECC model. In addition, it is found that the effect of coupling to positive Q-value neutron transfer channel is necessary to reproduce the sub-barrier fusion cross sections of the reactions $$^{18}$$ O + $$^{112,116,118}$$ Sn. While for $$^{18}$$ O + $$^{124}$$ Sn, the effect of coupling to neutron transfer channel with positive Q value can be neglected.