DOUBLY-EXCITED P(E) AND D(0) FESHBACH RESONANCES IN THE LITHIUM ISOELECTRONIC SEQUENCE

The Feshbach projection method and the generalized saddle-point technique have been used to obtain energies of P-4,2(e) and 4,2D(o) Feshbach resonances in He-, Li, and Be+. The results from both methods confirm each other. Positions and Auger energies of 31 resonances (3 in He-, 14 in Li, and 14 in Be+) lying between the 2 P-1(o) and 3 P-3(o) thresholds are given. These data can serve as a basis for identification of those resonances in future experiments. Some suggestions for such experiments are made.