Journal of Atomic, Molecular, and Optical Physics

Volume 2011 (2011), Article ID 696382, 6 pages

http://dx.doi.org/10.1155/2011/696382

Research Article

## Nonresonant Cross-Section, Fano-Shape Parameter and Correlation Coefficient for the Photoionization of 2s2p () in Heliumlike

Laboratory Atoms Lasers, Department of Physics, Cheikh Anta Diop University, 5005 Dakar, Senegal

Received 13 August 2010; Revised 1 November 2010; Accepted 6 December 2010

Academic Editor: Igor Bray

Copyright © 2011 Aliou Niane et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

#### Linked References

- R. P. Madden and K. Codling, “New autoionizing atomic energy levels in He, Ne, and Ar,”
*Physical Review Letters*, vol. 10, no. 12, pp. 516–518, 1963. View at Publisher · View at Google Scholar · View at Scopus - P. R. Woodruff and J. A. R. Samson, “Measurements of partial cross sections and autoionization in the photoionization of helium to ${\text{He}}^{\text{+}}$($\text{N}=2$),”
*Physical Review A*, vol. 25, no. 2, pp. 848–856, 1982. View at Publisher · View at Google Scholar · View at Scopus - H. D. Morgan and D. L. Ederer, “Photoionization cross section of helium for photon energies 59–67 eV: the ${(sp,2n+)}^{1}{P}^{o}$ Rydberg series of autoionizing resonances,”
*Physical Review A*, vol. 29, no. 4, pp. 1901–1906, 1984. View at Publisher · View at Google Scholar · View at Scopus - D. W. Lindle, T. A. Ferrett, P. A. Heimann, and D. A. Shirley, “Complete photoemission study of the He $1{\text{s}}^{2}\to 3\text{s}3\text{p}$ autoionizing resonance,”
*Physical Review A*, vol. 36, no. 5, pp. 2112–2119, 1987. View at Publisher · View at Google Scholar · View at Scopus - H. Kossmann, B. Krässig, and V. Schmidt, “New determination of Beutler-Fano parameters for the 3s3p ${}^{1}\text{P}{}_{1}$ resonance in helium,”
*Journal of Physics B*, vol. 21, no. 9, pp. 1489–1497, 1988. View at Publisher · View at Google Scholar · View at Scopus - M. Zubek, G. C. King, P. M. Rutter, and F. H. Read, “Photoionisation studies of autoionising states of helium between 69 and 77 eV,”
*Journal of Physics B*, vol. 22, no. 21, pp. 3411–3421, 1989. View at Publisher · View at Google Scholar · View at Scopus - M. Zubek, A. G Dawber, R. I. Hall, L. Avaldi, K. Ellis, and G. C. King, “Angular distribution of photoelectrons from ionization of helium into the ${\text{He}}^{\text{+}}$ ($\text{N}=2$) states, between 69 and 77 eV,”
*Journal of Physics B*, vol. 24, no. 14, p. L337, 1992. View at Publisher · View at Google Scholar - M. Domke, C. Xue, A. Puschmann et al., “Extensive double-excitation states in atomic helium,”
*Physical Review Letters*, vol. 66, no. 10, pp. 1306–1309, 1991. View at Publisher · View at Google Scholar · View at Scopus - M. Domke, G. Remmers, and G. Kaindl, “Observation of the $(sp,nd){}^{1}P{}^{\circ}$ double-excitation Rydberg series of helium,”
*Physical Review Letters*, vol. 69, no. 8, pp. 1171–1174, 1992. View at Publisher · View at Google Scholar · View at Scopus - M. Domke, K. Schulz, G. Remmers, A. Gutiérrez, G. Kaindl, and D. Wintgen, “Interferences in photoexcited double-excitation series of He,”
*Physical Review A*, vol. 51, no. 6, pp. R4309–R4312, 1995. View at Publisher · View at Google Scholar · View at Scopus - M. Domke, K. Schulz, G. Remmers, G. Kaindl, and D. Wintgen, “High-resolution study of P double-excitation states in helium,”
*Physical Review A*, vol. 53, no. 3, pp. 1424–1438, 1996. View at Google Scholar · View at Scopus - K. Schulz, G. Kaindl, M. Domke et al., “Observation of new rydberg series and resonances in doubly excited helium at ultrahigh resolution,”
*Physical Review Letters*, vol. 77, no. 15, pp. 3086–3089, 1996. View at Google Scholar · View at Scopus - R. Moccia and P. Spizzo, “An ${\text{L}}^{2}$ calculation of the ${}^{\text{1,3}}{\text{P}}^{\text{0}}$ resonances of atomic helium,”
*Journal of Physics B*, vol. 20, no. 7, pp. 1423–1431, 1987. View at Publisher · View at Google Scholar · View at Scopus - C. F. Fischer and M. Idrees, “Spline methods for resonances in photoionization cross sections,”
*Journal of Physics B*, vol. 23, no. 4, p. 679, 1990. View at Google Scholar - T. N. Chang, “He photoionization to the doubly excited (
*2pnd*) and $(sp,2{n}^{-}){}^{1}P{}^{\circ}$ series,”*Physical Review A*, vol. 47, no. 4, pp. 3441–3443, 1993. View at Publisher · View at Google Scholar · View at Scopus - J. Macek, “Properties of autoionizing states of He,”
*Journal of Physics B*, vol. 1, no. 5, pp. 831–843, 1968. View at Publisher · View at Google Scholar · View at Scopus - C. D. Lin, “Correlations of excited electrons. The study of channels in hyperspherical coordinates,”
*Physical Review A*, vol. 10, no. 6, pp. 1986–2001, 1974. View at Publisher · View at Google Scholar · View at Scopus - C. D. Lin and J. H. Macek, “Radial and angular correlations of two excited electrons. IV. Comparison of configuration-interaction wave functions with the group-theoretical basis functions,”
*Physical Review A*, vol. 29, no. 5, pp. 2317–2321, 1984. View at Publisher · View at Google Scholar · View at Scopus - C. D. Lin, “Classification of doubly excited states of two-electron atoms,”
*Physical Review Letters*, vol. 51, no. 15, pp. 1348–1351, 1983. View at Publisher · View at Google Scholar - C. D. Lin, “Hyperspherical coordinate approach to atomic and other Coulombic three-body systems,”
*Physics Report*, vol. 257, no. 1, pp. 1–83, 1995. View at Google Scholar - J. Z. Tang and I. Shimamura, “Mechanism of the enhancement of some high-lying resonance series in the photoionization spectra of excited helium,”
*Physical Review A*, vol. 50, no. 2, pp. 1321–1327, 1994. View at Publisher · View at Google Scholar · View at Scopus - H. R. Sadeghpour, “Nonadiabatic selection rules for the photoabsorption of ${\text{H}}^{-}$ and He,”
*Physical Review A*, vol. 43, no. 11, pp. 5821–5831, 1991. View at Publisher · View at Google Scholar · View at Scopus - T. Morishita, K. I. Hino, S. Watanabe, and M. Matsuzawa, “Proton-antiproton impact-electron emission spectra of He: comparison of theory with experiment,”
*Physical Review A*, vol. 53, no. 4, pp. 2345–2358, 1996. View at Google Scholar · View at Scopus - D. H. Oza, “Phase shifts and resonances for electron scattering by ${\text{He}}^{\text{+}}$ below the $\text{N}=2$ threshold,”
*Physical Review A*, vol. 33, no. 2, pp. 824–838, 1986. View at Publisher · View at Google Scholar · View at Scopus - S. Salomonson, S. L. Carter, and H. P. Kelly, “Calculation of helium photoionization with excitation including angular distribution and resonance structure,”
*Physical Review A*, vol. 39, no. 10, pp. 5111–5126, 1989. View at Publisher · View at Google Scholar · View at Scopus - B. Zhou, C. D. Lin, J.-Z. Tang, S. Watanabe, and M. Matsuzawa, “A hyperspherical close-coupling calculation of photoionization from the He atom, ${\text{Li}}^{\text{+}}$ and $\text{C}{4}^{+}$ ions. I. Below the $\text{N}=2$ threshold,”
*Journal of Physics B*, vol. 26, no. 16, p. 2555, 1993. View at Publisher · View at Google Scholar - K. A. Berrington, P. G. Burke, W. C. Fon, and K. T. Taylor, “Photoionisation of helium,”
*Journal of Physics B*, vol. 15, no. 17, pp. L603–L608, 1982. View at Publisher · View at Google Scholar · View at Scopus - J. Yan, Y.-Z. Qu, L. Voky, and J.-M. Li, “Polarization effect on He doubly excited states below the $\text{N}=2$ threshold of ${\text{He}}^{\text{+}}$,”
*Physical Review A*, vol. 57, no. 2, pp. 997–1005, 1998. View at Google Scholar - T. W. Gorczyca, J. E. Rubensson, C. Såthe et al., “Radiative and relativistic effects in the decay of highly excited states in helium,”
*Physical Review Letters*, vol. 85, no. 6, pp. 1202–1205, 2000. View at Publisher · View at Google Scholar · View at Scopus - Y. Jiang, J. Yan, J. Li, J. Sun, and L. Wan, “Photoionization of helium between the $\text{N}=2$ and $\text{N}=5$ thresholds of ${\text{He}}^{\text{+}}$: partial differential cross sections,”
*Physical Review A*, vol. 61, no. 3, Article ID 032721, 7 pages, 2000. View at Google Scholar - H. W. van der Hart and C. H. Greene, “Regularities and irregularities in partial photoionization cross sections of He,”
*Physical Review A*, vol. 66, no. 2, Article ID 022710, 8 pages, 2002. View at Google Scholar - T. Schneider, C.-N. Liu, and J.-M. Rost, “Intermanifold similarities in partial photoionization cross sections of helium,”
*Physical Review A*, vol. 65, no. 4, Article ID 042715, 9 pages, 2002. View at Google Scholar - Y. K. Ho, “Complex-coordinate calculations for doubly excited states of two-electron atoms,”
*Physical Review A*, vol. 23, no. 5, pp. 2137–2149, 1981. View at Google Scholar - Y. K. Ho, “Resonance positions and widths of doubly excited ${\text{N}}^{5+}$ ions associated with $\text{N}=3$, 4, and 5 ${\text{N}}^{6+}$ thresholds,”
*Physical Review A*, vol. 35, no. 5, pp. 2035–2043, 1987. View at Publisher · View at Google Scholar - Y. K. Ho, “High-lying doubly excited ${}^{1}P{}^{\circ}$ states of ${\text{H}}^{-}$,”
*Physical Review A*, vol. 45, no. 1, pp. 148–153, 1992. View at Publisher · View at Google Scholar - D. Wintgen and D. Delande, “Double photoexcitation of ${}^{1}P{}^{\circ}$ states in helium,”
*Journal of Physics B*, vol. 26, no. 14, p. L399, 1993. View at Google Scholar - A. K. Bhatia and A. Temkin, “Calculation of autoionization of He and ${\text{H}}^{-}$ using the projection-operator formalism,”
*Physical Review A*, vol. 11, no. 6, pp. 2018–2024, 1975. View at Publisher · View at Google Scholar · View at Scopus - A. K. Bhatia and A. Temkin, “Line-shape parameters for P1 Feshbach resonances in He and ${\text{Li}}^{\text{+}}$,”
*Physical Review A*, vol. 29, no. 4, pp. 1895–1900, 1984. View at Publisher · View at Google Scholar · View at Scopus - H. Bachau, “Position and widths of autoionising states in the helium isoelectronic sequence above the $\text{N}=2$ continuum,”
*Journal of Physics B*, vol. 17, no. 9, pp. 1771–1784, 1984. View at Publisher · View at Google Scholar · View at Scopus - A. Macías, F. Martín, A. Riera, and M. Yánez, “Simple discretization method for autoionization widths. II. Atoms,”
*Physical Review A*, vol. 36, no. 9, pp. 4187–4202, 1987. View at Publisher · View at Google Scholar · View at Scopus - V. V. Balashov, S. I. Grishanova, I. M. Kruglova, and V. S. Shenashenko, “Resonance photoionizationof helium and helium-like ions,”
*Optics and Spectroscopy*, vol. T28, no. 3, pp. 466–471, 1970, English Translation from Opt. Spektrosk, vol. 28. pp. 859–868, 1970. View at Google Scholar - A. Wagué, “Application of the diagonalization approximation to the $\text{n}=2$ resonant photoionization of helium-like systems,”
*Zeitschrift für Physik D*, vol. 6, no. 4, pp. 337–344, 1987. View at Publisher · View at Google Scholar · View at Scopus - N. A. B. Faye and A. Wagué, “Doubly-excited state resonances of the helium-like nitrogen ion ${\text{N}}^{5+}$ near the $\text{n}=3$ threshold of ${\text{N}}^{6+}$,”
*Zeitschrift für Physik D*, vol. 31, no. 1, pp. 37–40, 1994. View at Publisher · View at Google Scholar - N. A. B. Faye and A. Wague, “Resonant photoionization of ${\text{O}}^{6+}$ below the $\text{n}=2$ threshold of the reduced ion,”
*Journal of Physics B*, vol. 28, no. 9, pp. 1735–1742, 1995. View at Google Scholar - A. S. Ndao, A. Wagué, N. A.B. Faye, and A. Konté, “High-lying ${}^{\text{1,3}}{\text{P}}^{\text{0}}$ resonance states of He ($\text{n}=4$) and ${\text{H}}^{-}$($\text{n}=5$),”
*European Physical Journal D*, vol. 5, no. 3, pp. 327–334, 1999. View at Google Scholar - M. Biaye, A. Konté, A. S. Ndao, N. A. B. Faye, and A. Wagué, “The singlet doubly excited ${(nl)}^{2}$ states of helium-like systems,”
*Physica Scripta*, vol. 71, no. 1, pp. 39–42, 2005. View at Google Scholar · View at Scopus - N. A. B. Faye, A. S. Ndao, A. Konté, M. Biaye, and A. Wague, “Energy levels in the resonant photoionization of heliumlike ${\text{Ne}}^{8+}$,”
*Physical Review A*, vol. 75, no. 4, Article ID 042713, 5 pages, 2007. View at Publisher · View at Google Scholar - G. Tanner, K. Richter, and J. M. Rost, “The theory of two-electron atoms: between ground state and complete fragmentation,”
*Reviews of Modern Physics*, vol. 72, no. 2, pp. 497–544, 2000. View at Google Scholar · View at Scopus - Z.-S. Yuan, X.-Y. Han, X.-J. Liu et al., “Theoretical investigations on the dynamical correlation in double excitations of helium by the R-matrix method,”
*Physical Review A*, vol. 70, no. 6, Article ID 062706, 2004. View at Publisher · View at Google Scholar - X. W. Fan and K. T. Leung, “Momentum-transfer dependence of Fano parameters for the ${(1{\text{s}}^{2})}^{1}\text{S}\to {(2\text{s}2\text{p})}^{1}\text{P}$ doubly excited transition in helium,”
*Journal of Physics B*, vol. 34, no. 5, pp. 811–818, 2001. View at Publisher · View at Google Scholar - K. C. Prince, R. Richter, M. de Simone, M. Alagia, and M. Coreno, “Photoabsorption cross section and ion-yield spectra of helium double-excitation resonances,”
*Physical Review A*, vol. 68, no. 4, Article ID 044701, 4 pages, 2003. View at Google Scholar · View at Scopus - P. K. Carroll and E. T. Kennedy, “Doubly excited autoionization resonances in the absorption spectrum of ${\text{Li}}^{\text{+}}$ formed in a laser-produced plasma,”
*Physical Review Letters*, vol. 38, no. 19, pp. 1068–1071, 1977. View at Publisher · View at Google Scholar · View at Scopus - S. W. J. Scully, I. Álvarez, C. Cisneros et al., “Doubly excited resonances in the photoionization spectrum of ${\text{Li}}^{\text{+}}$,”
*Journal of Physics: Conference Series*, vol. 58, no. 1, pp. 387–390, 2007. View at Publisher · View at Google Scholar - P. L. Altick and E. N. Moore, “Configuration interaction in the helium continuum,”
*Physical Review*, vol. 147, no. 1, pp. 59–65, 1966. View at Publisher · View at Google Scholar · View at Scopus - P. G. Burke and D. D. McVicar, “Resonances in e-He scattering and the photoionization of He,”
*Proceedings of the Physical Society*, vol. 86, no. 5, pp. 989–1006, 1965. View at Publisher · View at Google Scholar · View at Scopus - I. Sanchez and F. Martin, “Photoionization of He-like systems below the $\text{N}=2$ threshold,”
*Journal of Physics B*, vol. 23, no. 23, p. 4263, 1990. View at Publisher · View at Google Scholar - S. Diehl, D. Cubaynes, J. M. Bizau et al., “New high-resolution measurements of doubly excited states of ${\text{Li}}^{\text{+}}$,”
*Journal of Physics B*, vol. 32, no. 17, pp. 4193–4207, 1999. View at Publisher · View at Google Scholar · View at Scopus - U. Fano, “Effects of configuration interaction on intensities and phase shifts,”
*Physical Review*, vol. 124, no. 6, pp. 1866–1878, 1961. View at Publisher · View at Google Scholar · View at Scopus - U. Fano and J. W. Cooper, “Line profiles in the far-uv absorption spectra of the rare gases,”
*Physical Review*, vol. 137, no. 5, pp. A1364–A1379, 1965. View at Publisher · View at Google Scholar · View at Scopus