Application of the relativistic random-phase approximation to Xe 5s photoionization

Recent experiments on the Xe 5s parameter in the vicinity of the Cooper minimum have shown a marked disagreement with truncated 13-channel relativistic random-phase approximation (RRPA) calculations. RRPA calculations including 26 channels have been performed. The results show that the truncation is not responsible for the disagreement, which must be due to non-RRPA correlations. © 1985 The American Physical Society.