E6transition inFe53

The ${\frac{19}{2}}^{-}\to {\frac{7}{2}}^{-}$ $E6\mathrm{}$ transition in ${}_{}{}^{53}{}_{}{}^{}\mathrm{Fe}$ is calculated in a model including all basis states of the configurations ${{\left(f_{\frac{7}{2}}\right)}^{13}}_{\mathrm{IT}}$ and ${[{{\left(f_{\frac{7}{2}}\right)}^{12}}_{I^{\prime }{T}^{\prime }}\times f_{\frac{5}{2}}]}_{\mathrm{IT}}$. Several interactions, which yield the observed amount of $f_{\frac{5}{2}}$ configuration mixing, have been considered. In all cases an effective charge $\delta \cong -0.4\mathrm{}$ is needed to fit experiment (where $e_p=1+\delta$, $e_n=\delta$).