Enhanced fusion-evaporation cross sections in neutron-rich [formula presented] on [formula presented]

Evaporation residue cross sections have been measured with neutron-rich radioactive [Formula presented] beams on [Formula presented] in the vicinity of the Coulomb barrier. The average beam intensity was [Formula presented] particles per second and the smallest cross section measured was less than 5 mb. Large sub-barrier fusion enhancement was observed. Coupled-channel calculations taking into account inelastic excitation significantly underpredict the measured cross sections below the barrier. The presence of several neutron transfer channels with large positive [Formula presented] values suggests that multinucleon transfer may play an important role in enhancing the fusion of [Formula presented] and [Formula presented].