Search for positron quasibound states in the doubly excited region of the helium atom

J. R. Machacek; R. Boadle; S. J. Buckman; J. P. Sullivan

doi:10.1103/PhysRevA.86.064702

Search for positron quasibound states in the doubly excited region of the helium atom

J. R. Machacek^*, R. Boadle, S. J. Buckman, J. P. Sullivan

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

13 Citations (Scopus)

Abstract

Recent calculations by Bromley have indicated that the He(2s21Se) state will bind a positron. The e⁺He(2s21Se) state has a binding energy of 0.447 eV with respect to the He(2s21Se) state. Binding of a positron to the He 2s2 state has been predicted to give rise to two resonances in positron scattering from ground-state helium: e⁺He(2s21Se) at 57.3716 eV and a 2Po shape resonance just above the He(2s21Se) threshold at 57.8485 eV. To investigate these predicted resonances, low-energy positron scattering experiments were performed to measure the total and positronium cross sections in the doubly excited region of helium in this energy region. No experimental evidence has been found for these resonances, but upper bounds on the resonance strength were determined for both predicted resonances.

Original language	English
Article number	064702
Journal	Physical Review A - Atomic, Molecular, and Optical Physics
Volume	86
Issue number	6
DOIs	https://doi.org/10.1103/PhysRevA.86.064702
Publication status	Published - 5 Dec 2012

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title = "Search for positron quasibound states in the doubly excited region of the helium atom",

abstract = "Recent calculations by Bromley have indicated that the He(2s21Se) state will bind a positron. The e+He(2s21Se) state has a binding energy of 0.447 eV with respect to the He(2s21Se) state. Binding of a positron to the He 2s2 state has been predicted to give rise to two resonances in positron scattering from ground-state helium: e+He(2s21Se) at 57.3716 eV and a 2Po shape resonance just above the He(2s21Se) threshold at 57.8485 eV. To investigate these predicted resonances, low-energy positron scattering experiments were performed to measure the total and positronium cross sections in the doubly excited region of helium in this energy region. No experimental evidence has been found for these resonances, but upper bounds on the resonance strength were determined for both predicted resonances.",

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AU - Machacek, J. R.

AU - Boadle, R.

AU - Buckman, S. J.

AU - Sullivan, J. P.

PY - 2012/12/5

Y1 - 2012/12/5

N2 - Recent calculations by Bromley have indicated that the He(2s21Se) state will bind a positron. The e+He(2s21Se) state has a binding energy of 0.447 eV with respect to the He(2s21Se) state. Binding of a positron to the He 2s2 state has been predicted to give rise to two resonances in positron scattering from ground-state helium: e+He(2s21Se) at 57.3716 eV and a 2Po shape resonance just above the He(2s21Se) threshold at 57.8485 eV. To investigate these predicted resonances, low-energy positron scattering experiments were performed to measure the total and positronium cross sections in the doubly excited region of helium in this energy region. No experimental evidence has been found for these resonances, but upper bounds on the resonance strength were determined for both predicted resonances.

AB - Recent calculations by Bromley have indicated that the He(2s21Se) state will bind a positron. The e+He(2s21Se) state has a binding energy of 0.447 eV with respect to the He(2s21Se) state. Binding of a positron to the He 2s2 state has been predicted to give rise to two resonances in positron scattering from ground-state helium: e+He(2s21Se) at 57.3716 eV and a 2Po shape resonance just above the He(2s21Se) threshold at 57.8485 eV. To investigate these predicted resonances, low-energy positron scattering experiments were performed to measure the total and positronium cross sections in the doubly excited region of helium in this energy region. No experimental evidence has been found for these resonances, but upper bounds on the resonance strength were determined for both predicted resonances.

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DO - 10.1103/PhysRevA.86.064702

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JF - Physical Review A - Atomic, Molecular, and Optical Physics

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Search for positron quasibound states in the doubly excited region of the helium atom

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