C3-like models in the ionization of hydrogen by electron impact

J. M. RANDAZZO, S. OTRANTO AND G. GASANEO

Rio de Janeiro-Brasil

Conferencia; XIX International Conference on Atomic Physics (ICAP); 2004

Optics and Photonics Research Center, Universtiy of Sao Paulo

A significant progress in the description of the three body coulomb continuum state was done in the eighty’s, when the C3 wave function was introduced. The application of this function first in ion – atom collision [1] and later on electron – atom [2] and photo double ionization [3] shows the goodness and defeats of the model. In the case of electron - atom ionization it can be seen that for intermediate to high energies the main features of the triply differential cross sections (TDCS) can be properly described by the C3 model, at least for light targets like hydrogen and helium. For low to intermediate energies the model does not properly reproduce the physics of the problem. Different lines have been followed trying to improve the description of the two electron continuum by including the parts of the full Hamiltonian neglected by the C3 model. One of them tried to keep the same function modifying the Sommerfeld parameters through the introduction of momentadependent charges [4,5]. Another one proposed the use of a real dilation factor on some of the coordinates [6]. The calculations of TDCS for ionization of light neutral targets by electron impact using the modified Sommerfeld parameters were done in C3-Born [4,5]. A different line of work was followed by Jones and Madison by using a correlated eikonal initial state instead but keeping the original C3 in the final channel. As a result, improvements on the description of the angular distributions are observed at intermediate energies [7]. In this work we evaluate the TDCS for electron impact ionization of hydrogen. The initial state is represented by the Born and the eikonal approximations. The final state is represented by the above mentioned C3-like models. We compare the results obtained for high and intermediate impact energies with the different models for the initial and final state and discuss the role of respective correlations in the angular distributions. The theoretical results are compared with recent experimental data [8]. [1] C. R. Garibotti and J. E. Miraglia, Phys. Rev. A 21, 572 (1980). [2] M. Brauner, J. S. Briggs and H. Klar, Jour. Phys. B 22, 2265 (1989) [3] F. Maulbetsch and J. S. Briggs Jour. Phys. B 26, 1679 (1993) [4] J. Berakdar and J. S. Briggs, Phys. Rev. Lett 72, 24 (1994), J. Berakdar, Phys. Rev. A 53, 2314 (1996), [5] Z. Chen et al., Phys. Rev. A 56, 4 (1997). [6] S. Otranto and C. R. Garibotti, Eur. Phys. J. D 21, 285 (2002). [7] S. Jones and D. H. Madison, Phys. Rev. A 62, 42701 (2000)21, 572 (1980). [2] M. Brauner, J. S. Briggs and H. Klar, Jour. Phys. B 22, 2265 (1989) [3] F. Maulbetsch and J. S. Briggs Jour. Phys. B 26, 1679 (1993) [4] J. Berakdar and J. S. Briggs, Phys. Rev. Lett 72, 24 (1994), J. Berakdar, Phys. Rev. A 53, 2314 (1996), [5] Z. Chen et al., Phys. Rev. A 56, 4 (1997). [6] S. Otranto and C. R. Garibotti, Eur. Phys. J. D 21, 285 (2002). [7] S. Jones and D. H. Madison, Phys. Rev. A 62, 42701 (2000)22, 2265 (1989) [3] F. Maulbetsch and J. S. Briggs Jour. Phys. B 26, 1679 (1993) [4] J. Berakdar and J. S. Briggs, Phys. Rev. Lett 72, 24 (1994), J. Berakdar, Phys. Rev. A 53, 2314 (1996), [5] Z. Chen et al., Phys. Rev. A 56, 4 (1997). [6] S. Otranto and C. R. Garibotti, Eur. Phys. J. D 21, 285 (2002). [7] S. Jones and D. H. Madison, Phys. Rev. A 62, 42701 (2000)26, 1679 (1993) [4] J. Berakdar and J. S. Briggs, Phys. Rev. Lett 72, 24 (1994), J. Berakdar, Phys. Rev. A 53, 2314 (1996), [5] Z. Chen et al., Phys. Rev. A 56, 4 (1997). [6] S. Otranto and C. R. Garibotti, Eur. Phys. J. D 21, 285 (2002). [7] S. Jones and D. H. Madison, Phys. Rev. A 62, 42701 (2000)72, 24 (1994), J. Berakdar, Phys. Rev. A 53, 2314 (1996), [5] Z. Chen et al., Phys. Rev. A 56, 4 (1997). [6] S. Otranto and C. R. Garibotti, Eur. Phys. J. D 21, 285 (2002). [7] S. Jones and D. H. Madison, Phys. Rev. A 62, 42701 (2000)53, 2314 (1996), [5] Z. Chen et al., Phys. Rev. A 56, 4 (1997). [6] S. Otranto and C. R. Garibotti, Eur. Phys. J. D 21, 285 (2002). [7] S. Jones and D. H. Madison, Phys. Rev. A 62, 42701 (2000)et al., Phys. Rev. A 56, 4 (1997). [6] S. Otranto and C. R. Garibotti, Eur. Phys. J. D 21, 285 (2002). [7] S. Jones and D. H. Madison, Phys. Rev. A 62, 42701 (2000)21, 285 (2002). [7] S. Jones and D. H. Madison, Phys. Rev. A 62, 42701 (2000)62, 42701 (2000)