Generator coordinate method calculation of theE2 decay lifetime of shape isomers in the actinide region

We apply the generator coordinate method in a fully microscopic calculation of the E2 decay lifetime of the shape isomeric states of ${}_{}{}^{236}{}_{}{}^{}\mathrm{U}$, ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$, and ${}_{}{}^{240}{}_{}{}^{}\mathrm{Pu}$. The basis states have been generated by constrained Hartree-Fock Bardeen-Cooper-Schrieffer calculations with the ${\mathrm{SkM}}^{\mathrm{*}}$ force. Triaxial quadrupole deformations have been included. Implications upon the decay lifetime of the quasidegeneracy of the isomeric state and the one-phonon excitation in the first well are examined. © 1996 The American Physical Society.