Searching for nuclei on the edge of stability with multi-step fragmentation

Abstract: Exploring the limits of neutron binding in atomic nuclei remains a central focus of nuclear physics. However, the experimental determination of the neutron drip line is challenging because of the minuscule production cross sections of the most neutron-rich isotopes. We investigated the effectiveness of multi-step fragmentation for producing extremely neutron-rich nuclides at relativistic energies. We demonstrate that multi-step fragmentation dominates over single-step fragmentation in thick target experiments and can enhance the yields of drip line nuclei by several orders of magnitude in a realistic experiment using fragment separators. Such enhancements open new possibilities for locating drip lines above sodium, and thus significantly expand the research horizon.