Soft Dipole Resonance In The Neutron-Skin Nucleus He-6

A candidate For a son dipole resonance. a dipole oscillation mode between a core cluster and a neutron skin, was observed at E-x = 4 +/- 1 MeV and with a width of 4 +/- 1 MeV in He-6 via the Li-6(Li-7,Be-7) reaction at an incident energy of 65A MeV and forward scattering angles inducting 0 degrees. Its cross section is deduced to be sigma(0 degrees) = 0.9 +/- 0.2 mb/sr. This value is comparable to that of the giant dipole resonance simultaneously measured.