Giant $M1\mathrm{}$ resonance in ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}$

Highly polarized tagged photons were used to measure the distribution of $M1\mathrm{}$ transition strength in ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}$ at excitations between 6.7 and 8.7 MeV. A strength of $\Sigma \frac{g{\Gamma }_0^2\mathrm{}\left(M1\mathrm{}\right)\mathrm{}}{\Gamma }={11.2}_{-3.1\mathrm{}}^{+4.5\mathrm{}}$ eV corresponding to a $B\left(M1\mathrm{}\uparrow \right)$ of about $7.5{\mu }_0^2$ was observed centered at an excitation of 7.95 MeV. This distribution of $M1\mathrm{}$ strength can account for the giant magnetic dipole resonance predicted in ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}$.