Evidence for Resonance States of Lead Decaying Into Two Exit Channels with Counterbalancing Contributions

The analysis of the electrons emitted in the decay of the $6s^{2}6p^2+h\nu \to 6s6p^2\left({}_{}{}^4{}_{}{}^{}P_{\frac{1}{2}}^{}{}_{}{}^{}\right)n{p}_{\frac{3}{2}}$ resonance series of Pb shows that negative contributions occur in the $6p^{-1\mathrm{}}{}_{}{}^2{}_{}{}^{}P_{\frac{1}{2}}^{}{}_{}{}^{}$ channel and positive contributions in the $6p^{-1\mathrm{}}{}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}$ channel due to interference with the direct photoionization process. These contributions effectively cancel. Hence the series is difficult to observe in absorption, but can easily be delineated in emission.