A proton pairing isomer in 174Hf: Reinterpretation of data and support for the split prolate–oblate pairing approximation for deformed nuclei

Abstract

AbstractThe available data on the even–even isotope 174Hf are reinterpreted to conclude that the low-lying 02+ level, usually regarded as a “β vibration”, is actually a proton (2p–2 h) excitation known as a Pairing Isomer. This is the first identification of a Pairing Isomer based on Proton Nilsson Orbitals. Its identification demonstrates that Pairing Isomers can exist anywhere in the Nuclear Chart if the positioning of the Fermi Surface is favourable with respect to relevant Nilsson orbitals.