Nuclear Physics Division

Pairing is ubiquitous in physics. From superconductivity to quantum shell structure, coupling particles into pairs is one of nature's preferred ways to lower the energy of a system. New results obtained at the Radioactive Isotope Beam Factory (RIBF, Japan) with the MINOS device, which was conceived and constructed at Irfu, show for the first time that pairing also plays an important role in single-proton removal reactions from neutron-rich nuclei. These results show that proton-removal cross sections can be used as a tool to investigate pairing correlations for very neutron rich nuclei not accessible via spectroscopy. Indeed, the latter are produced in too small quantities to consider spectroscopy, studying the gammas emitted during de-excitation for example. This study was recently published in Physical Review Letters [1].

An international collaboration led by the institutes of CEA-IRFU and of RIKEN (Japan) demonstrates, for the first time, the exceptional stability of the very-neutron rich nickel-78 nucleus and its doubly-magic character. The experiment at RIKEN was made possible by the unique combination of the MINOS device developed at CEA-Irfu and the very exotic beams produced by the RIBF facility of the Japanese accelerator.These results are published in Nature [Nat19].