In Search of New Excited States of \(^{57}\)Cu

An experiment to search for new excited states in the proton-rich nucleus \(^{57}\mathrm {Cu}\) was performed at the Heavy Ion Laboratory of the University of Warsaw. This nucleus, with one valence proton outside the doubly magic \(^{56}\mathrm {Ni}\) core, offers a sensitive test of Shell Model predictions in interplay with collective effects, and its structure is essential for the production of heavier elements in the astrophysical rp-process. A fusion–evaporation reaction was employed using an 85 MeV beam of \(^{32}\mathrm {S}\) ions incident on a \(^{28}\mathrm {Si}\) target. The emitted \(\gamma \)-rays, neutrons, and light charged particles were detected with the EAGLE, NEDA, and DIAMANT arrays, respectively. No \(\gamma \)-ray lines corresponding to \(^{57}\mathrm {Cu}\) could be identified. An upper limit for the \(^{57}\mathrm {Cu}\) production cross section was estimated as \(\sigma = 3~\mu \mathrm {b}\). Abstract Published by the Jagiellonian University 2026 authors