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

Notes on doppler-shift lifetime measurements

Nuclear transition probability, B(E2), for 0g.s.+ – 2first+ transitions and deformation parameter, β2*

Core excitation in O18

The experimental techniques of measuring the mean lifetimes tau of excited nuclear states is reviewed. Emphasis is put on direct measurements of tau in the region 10-18-10-6 s, especially on techniques involving the observation of Doppler energy shifts of gamma -rays. Indirect methods of obtaining tau by measuring the widths or partial widths are discussed. Comparisons are made of the applicability, accuracy and reliability of the different experimental techniques.

https://iopscience.iop.org/article/10.1088/0034-4885/42/1/001/pdf

A.E. Litherland

Papers

Lifetimes of the low-lying levels of O18 and F18