Frequency and Alignment Classification of Multiple Band Crossings

Abstract

Experiments on 160 Yb indicate three negative-parity bands up to I^21h~. All three ex^ perience a band crossing around a frequency HOJ = 0.36 MeV, a value intermediate to those of the first and second yrast backbends. The i 13 / 2 band in 161 Yb is observed up to Y +0 , it also has a strong upbend at this intermediate frequency. The fingerprint of a band crossing based upon the crossing frequency and gain in aligned angular momentum is demonstrated and the results compared to cranking-mod el calculations to suggest quasiparticle assignments for the bands.

Backbending in theN=96 isotones

“…Similar crossings are predicted for the 5/2 + [642] bands in the other oddmass, N=97 isotones, at comparable frequencies and with analogous properties; they should be searched for experimentally by extending the knowledge of these bands to higher spins. A similar phenomenon has recently been noticed in the experimental spectrum of 161yb [47]. These crossings with higher orbits in the vi13/2 and 7zh9/2 bands in this frequency range which is apparent in Fig.…”

Entropy in hot161,162Dyand171Guttormsen1, Bjerve2, Hjorth‐Jensen3 et al. 2000Phys. Rev. CSelf Cite386400View full textAdd to dashboardCite

“…Similarly, the entropy S is also a function of T . In this section, we extract the exact level density from a simple theoretical model 3 . The Hamiltonian we use to obtain the eigenvalues and the level density ρ(E) is the simple pairing Hamiltonian…”

“…In high spin physics, the backbending phenomenon is a beautiful manifestation of the breaking of pairs. The mechanism is induced by Coriolis forces tending to align single particle angular momenta along the nuclear rotational axis [3,4]. Theoretical models also predict reduction in the pair correlations at higher temperatures [5][6][7].…”

Search for strongly deformed structures and observation of multiple nucleon alignments inW174

“…Though first nucleon alignments have been established and characterized in many deformed nuclei, the knowledge and understanding of subsequent alignments is limited, and discussions addressing the issue can be found for only a small number of nuclei, e.g., Refs. [15][16][17][18][19][20][21][22]. The characterization of nucleon alignments provides insight into the underlying configurations of rotational bands in addition to checking the validity of predictions of cranking calculations at high rotational frequencies.…”