Fusion reactions with the one-neutron halo nucleus 15 C

The structure of 15 C, with an s1/2 neutron weakly bound to a closed-neutron shell nucleus 14 C, makes it a prime candidate for a one-neutron halo nucleus. We have for the first time studied the cross section for the fusion-fission reaction 15 C + 232 Th at energies in the vicinity of the Coulomb barrier and compared it to the yield of the neighboring 14 C + 232 Th system measured in the same experiment. At sub-barrier energies, an enhancement of the fusion yield by factors of 2-5 was observed for 15 C, while the cross sections for 14 C match the trends measured for 12,13 C.