Levels above the 19/2- isomer in Cu71: Persistence of the N=40 neutron shell gap
Physical Review C - Nuclear Physics 79:3 (2009)
Abstract:
Two prompt γ rays of energies 2020 and 554 keV were observed in coincidence with delayed transitions depopulating the 19/2- isomer in the Z=29, N=42 Cu71 nucleus. The newly identified transitions are proposed to deexcite the 4776- and 5330-keV levels above the 19/2- isomer. Based on the comparison with the low-lying positive-parity states observed in the Z=42, N=50 Mo92 nucleus, spin and parity 23/2- are proposed for the 4776-keV level in Cu71. The high-energy, 2020-keV transition is interpreted as arising from the breaking of the N=40 neutron core. Shell-model calculations with a Ni56 core reproduce the (23/2-)→(19/2-) gap well, suggesting that the 23/2- state is dominated by πp3/2ν((fp)10(g9/2)4) configurations. The present result constitutes further evidence supporting the view that the N=40 subshell closure persists in Cu71, herewith challenging recent suggestions that the coupling of two or more proton or neutron quasiparticles induces a large polarization of the Ni68 core. © 2009 The American Physical Society.Structure of neutron-rich odd-mass127,129,131in populated in the decay of127,129,131Cd
Acta Physica Polonica B 40:3 (2009) 437-446
Abstract:
New level structures are proposed for neutron-rich127,129,131In populated in the decay of127,129,131Cd. No evidence for the presence of 1-particle- 2-hole intruder structures in the neutron-rich In isotopes is observed.Spectroscopy of exotic 121, 123, 125Ag produced in fragmentation reactions
European Physical Journal A 42:3 (2009) 407-413
Abstract:
Excited states in the neutron-rich 121, 123, 125Ag were studied via the fragmentation of a 136Xe beam at 120MeV/nucleon in a thick 9Be target. The levels in 121Ag were populated in the β decay of 121Pd while those assigned to 123, 125Ag were identified via isomer spectroscopy. The transitions identified in 121Ag are consistent with the γ-rays reported in 117, 119Ag. The newly observed transitions were placed in the level schemes of 123, 125Ag based on the analysis of γ-γ coincidences and the systematics. We attribute the onset of isomerism in the 123, 125Ag isotopes to the drop in energy of the negative-parity levels similar to the 5- state in the even-even Cd cores. The proposed level scheme for 125Ag is well described by the NuShellX shell model calculations. © Societá Italiana di Fisica / Springer-Verlag 2009.Identification of the g9/2-proton bands in the neutron-rich 71,73,75,77Ga nuclei
PHYSICAL REVIEW C 79:6 (2009) ARTN 064302
Nuclear Spins and Magnetic Moments of 71,73,75Cu: Inversion of π2p3/2 and π1f5/2 Levels in 75Cu
PHYSICAL REVIEW LETTERS 103:14 (2009) ARTN 142501