Gamma rays from 27.7-keVs-wave neutron resonance capture byFe56

We have measured distinguishable gamma rays for the transition to the ground state and to the first excited state following 27.7-keV $s$-wave neutron resonance capture by ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$ with a good signal-to-noise ratio, using a 60-${\mathrm{cm}}^3$ pure Ge detector. Partial radiation widths have been obtained for both transitions. It has been found that those widths are not comprehensible in the valency capture model. The results suggest that there is some possibility of core excitation in $s$-wave neutron resonance capture by ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$.