Nanosecond Isomeric Transitions inGd155

Abstract

The half-lives of the excited states at 86.5 and 105.3 keV in ${\mathrm{Gd}}^{155}$ have been determined as $T_{\frac{1}{2}}\left(86.5\mathrm{} \mathrm{keV}\right)=6.3\mathrm{}\pm 0.1$ nsec and $T_{\frac{1}{2}}\left(105.3\mathrm{} \mathrm{keV}\right)=1.18\mathrm{}\pm 0.02$ nsec. The results are compared with the theoretical calculations of $E1\mathrm{}$ transition rates taking into account the retarding effect of pairing correlations. The importance of taking into account wave-function components admixed by the Coriolis coupling is discussed.