The radiative widths, spins and parities of ten levels photoexcited by the ($\gamma ,{\gamma }^{\prime }$) reaction at excitation around 7 MeV in ${}_{}{}^{139}{}_{}{}^{}\mathrm{La}$, ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}$, ${}_{}{}^{141}{}_{}{}^{}\mathrm{Pr}$, ${}_{}{}^{142}{}_{}{}^{}\mathrm{Nd}$, ${}_{}{}^{144}{}_{}{}^{}\mathrm{Nd}$, ${}_{}{}^{205}{}_{}{}^{}\mathrm{Tl}$, and ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$, were measured. The $\gamma$ beam was produced by thermal-neutron capture in titanium, iron, cobalt, and copper. The spins of the resonance levels were obtained by angular-distribution measurements and the parities were determined by using a Compton polarimeter. These levels together with other resonance levels in $N\sim 82$ and $N\sim 126$ nuclei are discussed with regard to a possible connection to a giant $M1\mathrm{}$ resonance.

• Received 20 July 1972

DOI:https://doi.org/10.1103/PhysRevC.6.2276