Hexadecapole strength in the rare isotopes 74,76Kr

• DOI: 10.1016/j.physletb.2023.137932
• Publication Date: 2023-04-26T16:00:16Z
• Authors: M. Spieker; S.E. Agbemava; D. Bazin; S. Biswas; P.D. Cottle; P.J. Farris; A. Gade; T. Ginter; S. Giraud; K.W. Kemper; J. Li; W. Nazarewicz; S. Noji; J. Pereira; L.A. Riley; M. Smith; D. Weisshaar; R.G.T. Zegers
• Keywords: Nuclear Structure; BETA (programming language); Isotopes of tin

In the Ge-Sr mass region, isotopes with neutron number $N \leq 40$ are known to feature rapid shape changes both nucleon and angular momentum. To gain new insights into their structure, inelastic proton scattering experiments in inverse kinematics were performed on rare $^{74,76}$Kr. This work focuses observables related $J^{\pi} = 4^+_1$ states of Kr and, particular, hexadecapole degree freedom. By performing coupled-channels calculations, deformation parameters $\beta_4$ determined for $^{74,76}$Kr from cross sections. Two possible solutions found. A comparison predictions nuclear energy density functional theory, employing non-relativistic relativistic functionals, clearly favors large, positive solutions. These values unambiguously linked well deformed prolate configuration. Given $\beta_2 - \beta_4$ trend, established this work, it appears that could provide a sensitive measure shell structure.