EVIDENCE OF AN EXCITED ANGULAR-CORRELATION MODE IN HIGH-LYING HE

We report an ab initio calculation of the photoionization spectrum of He in the energy regime hitherto unexplored theoretically, namely, energies near the He+ (N) states up to N = 7. The recently reported experimental photoionization spectrum of He is fully reproduced by using our previously reported hyperspherical close-coupling method. We find clear evidence of an excited angular correlation mode that was presumably overlooked in the analysis of the experimental data. We also present a calculated spectrum below He+ (N = 7) as a reference for future experiments.