Atomic nuclei that merely exist

Research Project, 2023 – 2026

The quest for a description of atomic nuclei from first principles, i.e. basic nuclear interactions, is a formidable one due to the complexity of the strong interaction as manifest on the level of nucleons. The present proposal aims at experimentally exploring light nuclear systems at the limits of nuclear binding - the very limits of existence, at and even beyond the neutron drip-line. Here, new phenomena like clustering, haloes and multineutron correlations characterise the nuclear structure, making these systems excellent laboratories for detailed studies of the strong interaction in weakly bound, correlated systems. This will constrain modern theories, e.g. with respect to three- and four-nucleon forces.We will be studying multi-neutron decay, neutron pairing and correlations in very light, neutron-rich systems (a "neutron star" in the laboratory) and the properties of excited nuclei with exotic structures, challenging nuclear models. The prime tool for these studies is nuclear reactions at high and low energies with short-lived radioactive beams.The opportunities for this research are currently excellent, where upgraded facilities for delivering Radioactive Ion Beams like CERN-ISOLDE and the existing GSI facility in Darmstadt (currently operating the FAIR Phase-0 programme), can be combined with new instrumentation that we have developed for the FAIR facility.