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Title: Correlations in the high-energy photoeffect

Abstract

We examine correlations in high-energy photoeffect, utilizing a perturbative treatment of the effects beyond the independent particle approximation (IPA) in the high-energy photoionization of states with arbitrary values of the angular momenta l. The dominant mechanism of IPA breaking is discussed. The dependence of IPA breaking contributions on the parameters 1/Z and {alpha}Z is analyzed. In the general case the amplitude is expressed as a linear combination of IPA amplitudes. The development of precise experiments, together with the demonstration that there is substantial cancellation among the nonrelativistic partial correlations amplitudes in many cases, particularly for ground-state atoms, makes a relativistic approach to the problem desirable, even at relatively low values of photon energy.

Authors:
 [1];  [2]
  1. Petersburg Nuclear Physics Institute, St. Petersburg 188300 (Russian Federation)
  2. University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)
Publication Date:
OSTI Identifier:
20786300
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 72; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevA.72.062701; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; AMPLITUDES; ANGULAR MOMENTUM; APPROXIMATIONS; ATOMS; CORRECTIONS; CORRELATIONS; GROUND STATES; PERTURBATION THEORY; PHOTOIONIZATION; PHOTON-ATOM COLLISIONS; PHOTONS; RELATIVISTIC RANGE

Citation Formats

Drukarev, E. G., and Pratt, R. H. Correlations in the high-energy photoeffect. United States: N. p., 2005. Web. doi:10.1103/PHYSREVA.72.0.
Drukarev, E. G., & Pratt, R. H. Correlations in the high-energy photoeffect. United States. doi:10.1103/PHYSREVA.72.0.
Drukarev, E. G., and Pratt, R. H. Thu . "Correlations in the high-energy photoeffect". United States. doi:10.1103/PHYSREVA.72.0.
@article{osti_20786300,
title = {Correlations in the high-energy photoeffect},
author = {Drukarev, E. G. and Pratt, R. H.},
abstractNote = {We examine correlations in high-energy photoeffect, utilizing a perturbative treatment of the effects beyond the independent particle approximation (IPA) in the high-energy photoionization of states with arbitrary values of the angular momenta l. The dominant mechanism of IPA breaking is discussed. The dependence of IPA breaking contributions on the parameters 1/Z and {alpha}Z is analyzed. In the general case the amplitude is expressed as a linear combination of IPA amplitudes. The development of precise experiments, together with the demonstration that there is substantial cancellation among the nonrelativistic partial correlations amplitudes in many cases, particularly for ground-state atoms, makes a relativistic approach to the problem desirable, even at relatively low values of photon energy.},
doi = {10.1103/PHYSREVA.72.0},
journal = {Physical Review. A},
number = 6,
volume = 72,
place = {United States},
year = {Thu Dec 15 00:00:00 EST 2005},
month = {Thu Dec 15 00:00:00 EST 2005}
}
  • We investigate the total effect of correlations on photoionization of atomic states with nonzero orbital momentum in the nonrelativistic high-energy asymptotic limit, considering the exclusive case of the dominant final state of an initial neutral atom. We find that the substantial cancellation of the dominant intrashell correlations, which had been reported earlier, can be understood utilizing the closure properties satisfied by the eigenfunctions of the nonrelativistic Hamiltonian. Considering the sum of correlations with all states, occupied or not, we show that complete sum is equal to the contribution of the high-energy part of the continuum. Consequently there is a totalmore » cancellation between the contributions of the bound states (occupied and unoccupied) and the low-energy part of the continuum states. This means that the real correlations in the physical atom due to the sum rule over the occupied states can be also obtained as the negative of the sum of contributions of low-energy bound and continuum unoccupied states. We calculate this in the framework of the quantum-defect model. As we would expect, the results are close to those obtained earlier in particular cases by direct summation over the occupied states. However this approach also allows us to see that the sum of correlations over the occupied states is smaller than the dominant intrashell correlation. Hence, there is a partial cancellation between correlations with the occupied states. We can also obtain some limits on the correlation effects by considering calculations with the screened Coulomb functions. The role of correlations in the exclusive photoionization processes, also the modification of correlations in the case of atomic ions, is discussed.« less