Artículos de revistas
Annihilation Dynamics Of Positrons In Molecular Environments
Registro en:
Nuclear Instruments And Methods In Physics Research, Section B: Beam Interactions With Materials And Atoms. , v. 143, n. 1-2, p. 140 - 148, 1998.
0168583X
2-s2.0-0032474951
Autor
Da Silva E.P.
Germano J.S.E.
Lino J.L.S.
De Carvalho C.R.C.
Natalense A.P.P.
Lima M.A.P.
Institución
Resumen
We present recent results for positron-molecule scattering obtained with the Schwinger multichannel method. Our calculations include integral, differential and momentum transfer cross sections and the annihilation parameter Zeff for C2H2 and C2H4 molecules. We discuss a mechanism for annihilation of positrons in low-energy positron-molecule scattering. We interpret the annihilation process through virtual electronic excitation of the target combined with electronic cloud relaxation and virtual positronium formation. We study the influence of the first electronic state of the target on the cross section and on the annihilation parameter in C+-C2H2 scattering. © 1998 Elsevier Science B.V. All rights reserved. 143 1-2 140 148 Murphy, T.J., Surko, C.M., (1991) Phys. Rev. Lett., 67, p. 2954 Iwata, K., Greaves, R.G., Murphy, T.J., Tinkle, M.D., Surko, C.M., (1995) Phys. Rev. A, 51, p. 473 Da Silva, E.P., Germano, J.S.E., Lima, M.A.P., (1996) Phys. Rev. Lett., 77, p. 1028 Germano, J.S.E., Lima, M.A.P., (1993) Phys. Rev. A, 47, p. 3976 Joachain, C.J., (1975) Quantum Collision Theory, p. 594. , North-Holland, Oxford Da Silva, E.P., Germano, J.S.E., Lima, M.A.P., (1994) Phys. Rev. A, 49, pp. R1527 Fraser, P.A., (1968) Adv. Atom. Mol. Phys., 4, p. 63 Przybyla, D.A., Addo-Asah, W., Kauppila, W.E., Kwan, C.K., Stein, T.S., (1997) Positron Workshop on Low-Energy Positron and Positronium Physics, p. 26. , Nottingham Sueoka, O., Mori, S., (1986) J. Phys. B, 19, p. 4035 Herzberg, G., Molecular Spectra and Molecular Structure, p. 611. , Copyright 1966 by Litton Educational Publishing Sueoka, O., Mori, S., (1989) J. Phys. B, 22, p. 963