Study of the clustering structure of 19B by the use of fragmentation reaction

The clustering structure of neutron dripline nucleus 19B, which is predicted by the AMD model and the molecular orbital model, is investigated by studying the fragmentation reaction of 19B. We compare 19B fragmentation with 13B fragmentation in 19B + 14N and 13B + 14N reactions at 35 MeV/nucleon by using antisymmetrized molecular dynamics, where 13B has no clustering features in its structure. We find that the cluster structure of the 19B nucleus is reflected in its fragmentation, since more He and Li isotopes are produced in the 19B fragmentation in comparison with the case in 13B fragmentation. Furthermore, we compare the 19B fragmentation with 12C fragmentation in the 14N-target reaction at 35 MeV/nucleon. In the case of 12C fragmentation, the existence of the clustering excited states of 12C significantly affects the fragmentation process, since the production of α particles is largely due to fragmentation through these clustering excited states, while in the case of 19B fragmentation, we cannot find such clustering excited states through which 19B breaks up into clusters. (author)