Projects per year
Radioactive beams of O14 and O15 were used to populate the resonant states 1/2+, 5/2+ and 0-,1-,2- in the unbound F15 and F16 nuclei, respectively, by means of proton elastic scattering reactions in inverse kinematics. Based on their large proton spectroscopic factor values, the resonant states in F16 can be viewed as a core of O14 plus a proton in the 2s1/2 or 1d5/2 shell and a neutron in 1p1/2. Experimental energies were used to derive the strength of the 2s1/2-1p1/2 and 1d5/2-1p1/2 proton-neutron interactions. It is found that the former changes by 40% compared with the mirror nucleus N16, and the latter changes by 10%. This apparent symmetry breaking of the nuclear force between mirror nuclei finds explanation in the role of the large coupling to the continuum for the states built on an =0 proton configuration.