Parity of BoundJ=1Levels inPb208

Abstract
The parities of four bound J=1 levels in Pb208 that are strongly excited by γ rays were determined by observing the elastic scattering of plane-polarized photons. The levels at 5.51, 7.06, 7.08, and 7.33 MeV are excited by electric dipole radiation, and therefore have negative parity. The 1 assignment for the 7.06-MeV level is of particular significance because this level had previously been thought to contain about 36% of the M1 strength in Pb208.