6p Cooper minima in the photoionization in high-Z atoms

A zero in the photoionization transition matrix element is well-known as the Cooper minimum (CM) [1,2]. Owing to the spin-orbit forces, the non-relativistic CM splits to two or more zeros. The 6p→εd Cooper minimum splits into three, i.e., 6p1/2→εd3/2 ,6p3/2→εd3/2, 6p3/2→εd5/2; there is no zero in 6p→εs transition matrix element. In past, CM in the photoionization from the 6p subshell was investigated up to Z=100 with the application of Dirac-Slater methodology [3,4]. In this work the dynamics of the 6p CM in atoms up to Z=120 are studied including both relativity and many-particle correlations. The Dirac-Fock (DF) independent particle approximation [5] and the correlated relativistic random phase approximation (RRPA) [6] are employed for calculating the dipole photoionization matrix elements for Rn (Z=86), Ra (Z=88), No (Z=102), Cn(Z=112), Og (Z=118), and Ubn (Z=120). [1] J. W. Cooper, Phys. Rev. A, 128, 681 (1962). [2] W. R. Johnson and K. T. Cheng, Phys. Rev. A 20, 978 (1979). [3] S. T. Manson, C. J. Lee, R. H. Pratt, I. B. Goldberg, B. R. Tambe and A. Ron, Phys. Rev. A, 28,2885 (1983). [4] P. C. Deshmukh, B. R. Tambe and S. T. Manson, Austral. J. Phys. 39, 679 (1986). [5] M. Reiher and A. Wolf, Relativistic Quantum Chemistry: The Fundamental Theory of Molecular Science, 2nd Edition (Wiley-VCH, Wertheim, Germany, 2015). [6] W.R. Johnson and C.D. Lin, Phys. Rev. A, 20, 964 (1979).]