Transition probability from the ground to the first-excited 2+ state of even–even nuclides

Adopted values for the reduced electric quadrupole transition probability, B(E2)↑, from the ground state to the first-excited 2+ state of even–even nuclides are given in Table I. Values of τ, the mean life of the 2+ state; E, the energy; and β, the quadrupole deformation parameter, are also listed there. The ratio of β to the value expected from the single-particle model is presented. The intrinsic quadrupole moment, Q0, is deduced from the B(E2)↑ value. The product E×B(E2)↑ is expressed as a percentage of the energy-weighted total and isoscalar E2 sum-rule strengths.

Table II presents the data on which Table I is based, namely the experimental results for B(E2)↑ values with quoted uncertainties. Information is also given on the quantity measured and the method used. The literature has been covered to November 2000.

The adopted B(E2)↑ values are compared in Table III with the values given by systematics and by various theoretical models. Predictions of unmeasured B(E2)↑ values are also given in Table III.

Transition probability from the ground to the first-excited 2^+ state of even-even nuclides

Rotational bands and particle-hole excitations at very high spin

Microscopic study of the high-spin behaviour in selected A ~= 80 nuclei

The experimental and theoretical evidence for intrinsic reflection-asymmetric shapes in nuclei is reviewed. The theoretical methods discussed cover a wide spectrum, from mean-field theory and its extensions to algebraic and cluster approaches. The experimental data for nuclear ground states and at low and high spin, cited as evidence for reflection asymmetry, are collected and categorized. The extensive data on electric dipole transition moments and their theoretical interpretation are surveyed, along with available data on electric octupole moments. The evidence for reflection-asymmetric molecular states in light nuclei is summarized. The application of reflection-asymmetric theories to descriptions of the fission barrier, bimodal fission, superdeformation, and hyperdeformations is reviewed, and some other perspectives in the wider context of nuclear physics are also given. [S0034-6861(96)00102-X]

Intrinsic reflection asymmetry in atomic nuclei

In-beam study of 80Kr; Quasiparticle excitations in nuclei around mass 80

Several rotational bands have been populated to high spin in the \ensuremath{\gamma}-soft nucleus $^{131}\mathrm{La}$. We present expreimental evidence for a collective oblate rotational band based on a \ensuremath{\pi}${\mathrm{h}}_{11/2}$\ensuremath{\bigotimes}(\ensuremath{\nu}${\mathrm{h}}_{11/2}$${)}^{2}$ three-quasiparticle configuration. It is the rotational alignment of the pair of neutrons from the upper ${\mathrm{h}}_{11/2}$ midshell which drives the nucleus from a prolate (\ensuremath{\gamma}=0\ifmmode^\circ\else\textdegree\fi{}) shape to a collectively rotating oblate (\ensuremath{\gamma}=-60\ifmmode^\circ\else\textdegree\fi{}) shape. This band coexists with a prolate band that contains a pair of aligned protons from the lower ${\mathrm{h}}_{11/2}$ midshell.

L. Hildingsson

Papers

In-beam study of 80Kr; Quasiparticle excitations in nuclei around mass 80

Collective oblate band in La 131 due to the rotational alignment of h 1 1 / 2 neutrons

Shape change and fast M1 transitions in 81Kr

High-spin excitations of 187, 188Hg

Signature inversion in 120Cs: Evidence for a residual pn interaction