4843-keV,1+Level ofPb208

Abstract

From measurements of resonance-fluorescence cross section, angular distribution, and polarization, the 4843-keV level of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ has been shown to have a $1^{+}$ character and a width of 5.1 ± 0.8 eV with all of the decays to the ground state. As the probable lower member of the giant $M1\mathrm{}$ excitation, this state is at a significantly lower energy and has a decay strength which is an order of magnitude larger than the predictions of simple shell-model calculations.