A NEW SHAPE ISOMER IN THE N=Z NUCLEUS ⁷²KR

Low-lying levels in Cr59: Inadequacy of the fp model space and onset of deformation

“…There is an interesting parallel here between the A = 60 and A = 80 regions; the neutron Fermi surface has a similar position in terms of single-particle orbitals to that for both types of nucleons in the A = 80 region. In 72 Kr, for example, the large gap at Z = N = 36 results in an oblate ground state, but low-level density on the prolate side conspires to produce a prolate 0 + first-excited state [27]. Although the strong cooperative effects between protons and neutrons in the same orbitals is lacking in the A = 60 region, similar phenomena may occur.…”

E0 Transition Strengths in 70Se and 70Kr Mirror Nuclei within a Beyond-Mean-Field Model

“…The description of the coexisting configurations displaying different intrinsic deformations in the structure of the involved wave functions is a challenge and test for nuclear models. In recent years, E0 transitions have become a key observable in experiments and theoretical investigations [1][2][3][4][5][6][7][8][9][10][11]. More frequently, the E0 transitions between the 0 + states have been studied, but recently E0 transition strengths for the lowest few 2 + and 4 + states have been considered relevant fingerprints of shape coexistence and mixing.…”

“…More frequently, the E0 transitions between the 0 + states have been studied, but recently E0 transition strengths for the lowest few 2 + and 4 + states have been considered relevant fingerprints of shape coexistence and mixing. In the A = 70 region, shape coexistence and mixing have progressively become the fundamental defining characteristics of proton-rich nuclei [2][3][4][5][11][12][13][14][15][16][17][18][19].…”