Measurement of the total reaction cross section for the mirror nuclei ~(12)N and ~(12)B

The mirror nuclei ~(12)N and ~(12)B are separated by the Radioactive Ion Beam Line in Lanzhou (RIBLL)at HIRFL from the breakup of 78.6 MeV/u ~(14)N on a Be target. The total reaction cross-sections of ~(12)N at 34.9 MeV/u and ~(12)B at 54.4 MeV/u on a Si target have been measured by using the transmission method.Assuming ~(12)N consists of a ~(11)C core plus one halo proton, the excitation function of ~(12)N and ~(12)B on a Si target and a C target were calculated with the Glauber model. It can fit the experimental data very well. The characteristic halo structure for ~(12)N was found with a large diffusion of the protons density distribution.