On the widths of doubly excited states of the helium negative ion

A critical examination of some theoretical and experimental results on doubly excited resonances in helium has been made. It is concluded that the partial widths of the Rydberg series should vary approximately as n -3.254 , in variance with previous inferences. This estimate appears to be supported by semiclassical calculations of doubly excited two-electron systems, which give analytically Gamma approximately n -3 .