Structure of80Ge revealed by theβdecay of isomeric states in80Ga: Triaxiality in the vicinity of

D. Verney

¹

,

B. Tastet

²

,

K. Kolos

³

et al.

Probing nuclear structures in the vicinity of78Ni withβ- andβn-decay spectroscopy ofKolos1, Verney2, Ibrahim3 et al. 2013Phys. Rev. CSelf Cite

“…Understanding the structure of the Ge (Z = 32) neutron-rich isotopes close to N = 50 is of particular interest because a local energy minimum of the correlated gap (N = 50) = S 2n (N = 52) − S 2n (N = 50), as can be extracted, e.g., from the 2012 AMDC mass evaluation [5], is found exactly at Z = 32. This minimum seems to be associated with collective γ -soft structure in 80 Ge [6]. Further evidence for the survival of γ -softness close to and beyond N = 50 could in some way confirm the intuition of Lebois et al…”

“…By evaluating the n-body quadrupole moments in a similar way as in [6], the intrinsic parameters of the SM 0 + gs and 2 + 2 states are β rms = 0.213, γ rms = 23 • (strikingly similar to the 5DCH results) and β rms = 0.181, γ rms = 28 • respectively. Inspection of the main E2 transitions shows that the 2 + 2 state is the band head of a quasi-γ band.…”

“…The monopole part of the proton-neutron effective Hamiltonian was adjusted to ensure a correct propagation of the singleparticle states between 79 Ni and 91 Zr. Taking the protonproton part from the JJ4B interaction allows for a consistent discussion of the Z = 32 proton effects with results already obtained below N = 50 in [6]. Electromagnetic quantities were calculated using the effective charges e π = 1.6, e ν = 0.6 [as with those effective charges we obtained the best result for B(E2) for the N = 50 isotonic chain] and the gyromagnetic factors g π = 4.1895, g ν = −2.8695 [14,17,18].…”

“…In red are the transitions assigned from this experiment. (4) (1/2 + , 3/2 + ) 5.2(1.1) 1238.4 (8) (3/2 + , 5/2 + ) 1.1(3) 1452.7 (4) (1/2 + , 3/2 + , 5/2 + ) 0.8(3) 2026.4 (5) (1/2 + , 3/2 + , 5/2 + ) 1.1(4) 3238 (1) (1/2 + , 3/2 + , 5/2 + ) 0.8 (3) 0.0 0 + <29 >5.6(2) 624.2(2) 2 + 4.4(8) 6.3(1) 1389.3 (4) (1 + , 2 + ) 1.6(5) 6.5(2) 2228.1 (3) (0 + , 1 + , 2 + ) 1.1(3) 6.6(1) 3502.3 (6) (1 + , 2 + ) 5.1(1.2) 5.7 (1) of 2p 3/2 , 1f 5/2 , 2p 1/2 , 1g 9/2 orbits for protons and 1g 7/2 , 2d 5/2 , 2d 3/2 , 3s 1/2 , 1h 11/2 for neutrons. In this interaction the effective neutron-neutron and neutron-proton parts were taken from [15] while the proton-proton two-body matrix elements (TBMEs) were obtained from the JJ4B interaction [16].…”

Review of metastable states in heavy nuclei

“…Thus, in the case of 80 Ga, measurements at ISOLDE enabled the discovery of a new isomer [478], whose excitation energy remains unknown but whose decay properties have since been studied in detail [479].…”