Документ взят из кэша поисковой машины. Адрес оригинального документа : http://danp.sinp.msu.ru/LIIWM/JPhys_ConfSer194_8_082007_VAKho.pdf Дата изменения: Tue Feb 8 21:17:54 2011 Дата индексирования: Mon Oct 1 22:34:28 2012 Кодировка:

Home

Search

Collections

Journals

About

Contact us

My IOPscience

The role of scattering on atomic nucleus and of electron state entanglement in single ionization of He by ion impact

This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2009 J. Phys.: Conf. Ser. 194 082007 (http://iopscience.iop.org/1742-6596/194/8/082007) View the table of contents for this issue, or go to the journal homepage for more

Download details: IP Address: 213.131.6.105 The article was downloaded on 08/02/2011 at 18:11

Please note that terms and conditions apply.


XXVI International Conference on Photonic, Electronic and Atomic Collisions IOP Publishing Journal of Physics: Conference Series 194 (2009) 082007 doi:10.1088/1742-6596/194/8/082007

The role of scattering on atomic nucleus and of electron state entanglement in single ionization of He by ion impact
V.A. Kho dyrev
1

Institute of Nuclear Physics, Moscow State University, Moscow 119899, Russia
Synopsis The DWA scattering amplitude is presented in a form where different interactions are essentially separated. This form permits also to treat in the regular way the motion of nuclei quasiclassically. It is argued that, due to the entanglement of electron states, the screening by all except of the active electron is not effective.

Recently the data for single ionization in 100 MeV/amu C6+ +He collisions measured by reaction microscope have been mainly reconciled with the first Born description [1]. However, the treatment of elastic scattering in the semiclassical terms is not justified in the FBA picture. Also, the question is left why the distorted wave approaches (DWA) are not capable to reproduce some features of FDCS. These problems are addressed in the present contribution where a method is proposed how to separate different interactions in the DWA, to apply the quasiclassical approach for the pro jectile motion and, finally, to treat accurately the interaction with two electrons. The first problem is solved by insertion into the scattering matrix Tf i =< -f |Uif (R)|+i > p p (1)

в
p

+ fppf (|p| - |pf |) < p |Uif (R)|+i >; p

the sum of the closure relation for the states of the pro jectile scattering on the atomic core + : p Tf i =
p + < -f |p >< + |Uif (R)|+i > p p p

(2)

(Uif (R) in (1) is the matrix element for electron transition, R the pro jectile coordinates). The first factor in (2) is the scattering matrix for elastic scattering on the atomic core, < -f |+ >= p p = (p - pf ) + i fppf (|p| - |pf |), 2 pf (3)

the former presents mainly the scattering on electrons while the latter accounts for the sequential scattering on electrons and on the atomic core. At large energies the states + can be described by plane waves (as in FBA). The second advantage of (4) and (5) is that the entering matrix elements for the states of the same orthogonal basis can be treated quasiclassically [2]. The result is that the matrix elements are presented as Fourier transformation of the semiclassical transition amplitude. It is also en shown that Tf i is presented as a product of the amplitude of elastic scattering by the amplitude of electron transition. Thus we have a surprising e en result: two terms Tf i and Tf i commonly identified as alternative forms of the transition matrix must be summed in the correct result. Finally, as far as we treat the interaction of the pro jectile with both electrons as perturbation, the states ± should describe scattering on p the bare atomic nucleus (effective charge is equal to Z2 = 2). The consequence is that, in the elastic collisions, Uii (R) presents effect of screening of atomic nucleus modifying the scattering on the Coulomb potential. In inelastic scattering, due to the orthogonality of one-electron states, the transitions of different electrons are summed in the amplitude with all other electrons non-active. Such "undressing" effect is due to assumed entanglement of the states of atomic electrons and its signatures have been recognized in the measurements relating to the energy loss-deflection angle correlations [3]. References
Ё [1] Schulz M, Durr M., Na jjari B, Moshammer R, and Ullrich J 2007 Phys. Rev. A 76 032712. [2] Landau L D and Lifshitz E M 1977 Quantum Mechanics (Pergamon, Oxford). [3] Khodyrev V A 2004 Adv. Quant. Chem. 45 125.

where fppf is the ordinary amplitude of elastic scattering. With this the amplitude (2) is represented as a sum of two terms:
e Tf i

=< |Uif (R)|
en Tf i

+ pf

+i p

>,

(4) (5)

i в = 2 pf

1

E-mail: khodyrev@gmail.com

c 2009 IOP Publishing Ltd

1