Pb208(γ,n)Pb207and the GiantM1Resonance

Abstract

Photoneutron resonances and their angular distributions have been studied in a high-resolution measurement of the ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}(\gamma ,n){}_{}{}^{207}{}_{}{}^{}\mathrm{Pb}$ reaction near threshold. The angular distributions observed for lower-energy photoneutron resonances tend to confirm the conclusions of earlier experiments which suggest the existence of a giant $M1\mathrm{}$ resonance in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$.