Soft dipole resonance in the neutron-skin nucleus 6He

Phys Rev Lett. 2000 Jul 10;85(2):262-5. doi: 10.1103/PhysRevLett.85.262.

Abstract

A candidate for a soft dipole resonance, a dipole oscillation mode between a core cluster and a neutron skin, was observed at Ex = 4+/-1 MeV and with a width of 4+/-1 MeV in 6He via the 6Li( 7Li, 7Be) reaction at an incident energy of 65A MeV and forward scattering angles including 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.