Relativistic effects in photoionization: Wigner time delay for the noble gases and IIB atoms

Time delay in atomic photoionization has been observed in several experiments [1, 2], and various theoretical and experimental approaches are developing rapidly to obtain a better understanding of this phenomena [3]. Theoretical methods that account for many body correlations include the relativistic random phase approximation (RRPA) [4] and its non-relativistic analogue, RPAE [5]. Calculations using RRPA are performed and the impact of relativistic interactions on Wigner time delay are explored \textit{via} comparison of this result with RPAE results [6, 7]. In addition, results on Wigner time delay for Zn Cd and Hg are presented. [1] M Schultze \textit{et al}, \textit{Science} \textbf{328}, 1658 (2010). [2] K Kl\"{u}nder \textit{et al, PRL} \textbf{106}, 143002 (2011). [3] \quad R. Pazourek, \textit{et al}, Rev. Mod. Phys. \textbf{87}, 765 (2015) [4] W. R. Johnson, C. D. Lin, \textit{Phys. Rev. A} \textbf{20,} 964 (1979) [5] M.Y.Amusia, \textit{Atomic Photoeffect} (Plenum Press, New York, 1990). [6] A. S. Kheifets, Phys. Rev. A \textbf{87}, 063404 (2013). [7] A. Kheifets \textit{et al}, Phys. Rev. A \textbf{94}, 013423 (2016).