Dominance of correlation and relativistic effects on photodetachment time delay well above threshold

Wigner time delay in photodetachment from the $3p_{3/2}$ and $3p_{1/2}$ subshells of ${\mathrm{Cl}}^{-}$ has been studied in the vicinity of the $2p_{3/2}$ and $2p_{1/2}$ thresholds, using the relativistic random phase approximation (RRPA). The results show time delay spectra dominated by many-body correlations along with very complicated dependence on the energy over a broad spectral range. In addition, the time delay spectra of the two spin-orbit split $3p$ subshells differ significantly from one another, thereby revealing the importance of relativistic effects even in the case of a low-$Z$ system.

Figure 1

Photodetachment cross sections for the $3p_{1/2}$ subshell of ${\mathrm{Cl}}^{-}$ (upper panel) and the $3p_{3/2}$ subshell (lower panel) in the vicinity of the $2p$ thresholds calculated at the 14-channel (thick red curve) and 7-channel (thin black curve) levels as explained in the text. The $2p$ thresholds are indicated by vertical dashed lines.

Figure 2

Total photodetachment cross section and subshell cross sections calculated at the 14-channel level. The $2p$ thresholds are indicated by vertical dashed lines.

Figure 3

Phases of the $3p_{1/2}$ subshell of ${\mathrm{Cl}}^{-}$ (upper left panel) and the $3p_{3/2}$ subshell (upper right panel) and time delays (lower left and lower right panels, respectively) in the vicinity of the $2p$ thresholds calculated at the 14-channel (thick red curve) and 7-channel (thin black curve) levels as explained in the text. The $2p$ thresholds are indicated by vertical dashed lines.

Figure 4

Wigner time delay of the unresolved $3p$ subshell of ${\mathrm{Cl}}^{-}$ in the vicinity of the $2p$ thresholds calculated at the 14-channel (thick red curve) and 7-channel (thin black curve) levels as explained in text. The $2p$ thresholds are indicated by vertical dashed lines.