Effects of core correlations on the photodetachment of Cu$^{-}$

The photodetachment of anions is an excellent probe for many-electron correlation effects since the valence electron is only weakly attached to the atom. In the present study the RRPA [1] and MCTD method [2] are employed to investigate the core correlation effects on the photodetachment of Cu$^{-}$ (Z=29) in the low energy region. We included the core correlations by including double excitations from the core 3d subshells besides valence electron excitations. The GRASP92 [3] package was used to obtain the MCDF wave functions. Good agreement of MCTD results with experimental data [4] in the low energy region underlines the significance of core correlation effects. Using the RRPA, we have found a slight deviation of photoelectron angular distribution asymmetry parameter b$_{4s}$ from 2 [5] at the Cooper minimum, within the experimental errors. \\[4pt] [1]. W. R. Johnson and C. D. Lin, Phys. Rev. A \textbf{20}, 964 (1979). \\[0pt] [2]. V. Radojevic' and W. R. Johnson, Phys. Rev. A \textbf{31}, 2991 (1985). \\[0pt] [3]. F. A. Parpia \textit{et al.}, Comput. Phys. Commun. \textbf{94,} 249 (1996) \\[0pt] [4]. P. Balling \textit{et al.}, J. Phys. B \textbf{25}, L565 (1992). \\[0pt] [5]. G. Aravind \textit{et al.}, Phys. Rev. A. \textbf{79}, 043411 (2009).