Nuclei with the same number of neutrons and protons (N=Z) are prime objects to study effects of neutron-proton pairing and how much the (isospin) symmetry with regard to neutron-neutron and proton-proton forces is broken. Furthermore, beyond the N=Z=28 nucleus 56Ni, information on these nuclei is relevant for element production in the astrophysical rapid proton capture process as they are rapidly approaching the proton dripline, i.e. they become susceptible for proton emission. Physics topics are quantum tunneling of quasi-bound or unbound states and the influence of the latter on nuclear structure.
Based on the discovery of discrete-energy proton emission from excited states, i.e. competing with gamma-ray emission (see right-hand side), the group has developed research instrumentation for in-beam studies of prompt coincidences between charged particles detected with silicon strip detectors (DSSSDs, Lund Silicon Array) inside large germanium detector arrays (international infrastructure). See PhD theses of Corina Andreoiu, Lise-Lotte Andersson, and Emma K. Johansson for more details.
The latest LuSiA edition, i.e. two CD-type DSSSDs are currently (2020) mounted together with other charged particle detectors (Microball, cf. sketch below) and neutron detectors inside the GAMMASPHERE array at Argonne National Laboratory. They await an experiment campaign on the N=Z-1 isotopes 57Cu, 61Ga, and 65As - despite covid-19 hinders.