Rotational structures inTa177

Abstract

High-spin states in ' Ta were produced using the ' Er("B, 4n) reaction at 55 and 60 MeV. Considerable extensions have been made to the previously known level scheme, and new structures have been found. B(M1) B/(E2) ratios have been extracted for strongly coupled bands. The behavior of the different rotational cascades, in particular the anomalous crossing frequency observed in the [541]2 proton h9/2 band and the occurrence of "identical bands, " is discussed. Comparisons are made with projected shell model calculations.PACS number(s): 21.10. Re, 21.60.Cs, 23.20.Lv, 27.70.+q

Evolution of collective structures in the heavy transitional nuclei above the N = 82 closed shell

“…This splitting is attributed to triaxiality, which relieves the degeneracy of the high-Ω h 11/2 orbital. As the maximum number of valence neutrons is reached at N = 104, the α = +1/2 (13/2 − and 15/2 − ) states lie near the midpoints of the levels in the α = −1/2 signature partner [32,33]. This is interpreted as a restoration of signature degeneracy in the πh 11/2 orbital due to the onset of axial prolate symmetry arising from maximal correlations between nucleons at the neutron midshell.…”