Distribution ofM1Transitions inPb208

The distribution of $M1\mathrm{}$ strength in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ has been measured between 5.8 and 7.4 MeV with highly polarized tagged photons. $\Sigma \frac{{\Gamma }_0^2\mathrm{}\left(M1\mathrm{}\right)\mathrm{}}{\Gamma }={14.6}_{-1.3\mathrm{}}^{+1.5\mathrm{}}$ eV corresponding to $\Sigma B\left(M1\mathrm{}\uparrow \right)=\left({10.7}_{-0.9\mathrm{}}^{+1.1\mathrm{}}\right){\mu }_N^2$ was found, and can fully account for the much discussed "missing" $M1\mathrm{}$ in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$. When the present result is combined with known $1^{+}$ transitions above neutron threshold, an $M1\mathrm{}$ giant resonance emerges at 7.3 MeV, 1 MeV wide, with $\Sigma B\left(M1\mathrm{}\uparrow \right)\approx 15.6{\mu }_N^2$. Smaller $1^{+}$ resonances are also seen at both 5.85 and 6.24 MeV. The total $M1\mathrm{}$ strength below 6.4 MeV amounts to $\Sigma B\left(M1\mathrm{}\right)\mathrm{}=\left({1.9}_{-0.4\mathrm{}}^{+0.7\mathrm{}}\right){\mu }_N^2$.