Transmission resonance spectroscopy in the third minimum of 232Pa

The observation of discrete γ transitions between hy-perdeformed (HD) nuclear states represents one of thelast frontiers of high-spin physics. Although a large com-munity with 4π γ arrays was searching for HD states invery long experiments, no discrete HD γ transition wasfound in the mass region of A ≈100-130 [1–5]. On theother hand, the existence of low-spin hyperdeformationin the third minimum of the fission barrier is establishedboth experimentally and theoretically in the actinide re-gion [6, 7]. Observing transmission resonances as a func-tion of the excitation energy caused by resonant tunnel-ing through excited states in the third minimum of thepotential barrier can specify the excitation energies ofthe HD states. Moreover, the observed states could beordered into rotational bands and the moments of iner-tia of these bands can characterizethe underlying nuclearshape, proving that these states have indeed a HD con-figuration.Regarding hyperdeformation, the double-odd nucleus