One- and Two-Neutron Transfer Reactions in ¹¹Be+²⁰⁸Pb and Mechanism of Lowering Fusion Barrier

We study one- and two-neutron transfer reactions in ¹¹Be+²⁰⁸Pb by using the quantum molecular dynamics model. We find that lowering about 1-2 MeV of the potential barrier of ²⁰⁸Pb for fusion is gained when two neutrons separated from ¹¹Be enter into ²⁰⁸Pb. Whereas no significant change of potential barrier is found when only the halo neutron separated from ¹¹Be enters into ²⁰⁸Pb. The dynamical interplay between suppression and enhancement effects on the fusion probability in reaction ¹¹Be+²⁰⁸Pb stemming from the easy separation of halo neutron and the long extending of neutron distribution is discussed.