@Article{Delafosse_etal2018,
author="Delafosse, C. et al
and Gadea, A.
and Perez-Vidal, R. M.
and Domingo-Pardo, C.",
title="Pseudospin Symmetry and Microscopic Origin of Shape Coexistence in the Ni-78 Region: A Hint from Lifetime Measurements",
journal="Physical Review Letters",
year="2018",
publisher="Amer Physical Soc",
volume="121",
number="19",
pages="192502--7pp",
abstract="Lifetime measurements of excited states of the light N = 52 isotones Kr-88, Se-86, and Ge-84 have been performed, using the recoil distance Doppler shift method and VAMOS and AGATA spectrometers for particle identification and gamma spectroscopy, respectively. The reduced electric quadrupole transition probabilities B(E2; 2(+)-> 0(+)) and B(E2; 4(+)-> 2(+)) were obtained for the first time for the hard-to-reach 84Ge. While the B(E2; 2(+)-> 0(+) ) values of Kr-88, Se-86 saturate the maximum quadrupole collectivity offered by the natural valence (3s, 2d, 1g(7/2), 1h(11/2)) space of an inert Ni-78 core, the value obtained for Ge-84 largely exceeds it, suggesting that shape coexistence phenomena, previously reported at N less than or similar to 49, extend beyond N = 50. The onset of collectivity at Z = 32 is understood as due to a pseudo-SU(3) organization of the proton single-particle sequence reflecting a clear manifestation of pseudospin symmetry. It is realized that the latter provides actually reliable guidance for understanding the observed proton and neutron single particle structure in the whole medium-mass region, from Ni to Sn, pointing towards the important role of the isovector-vector rho field in shell-structure evolution.",
optnote="WOS:000449791600008",
optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=3800), last updated on Tue, 27 Nov 2018 13:32:59 +0000",
issn="0031-9007",
doi="10.1103/PhysRevLett.121.192502",
opturl="https://doi.org/10.1103/PhysRevLett.121.192502",
language="English"
}