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

Machacek, Joshua; Boadle, Roisin; Buckman, Stephen; Sullivan, James

Description

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...[Show more]

dc.contributor.authorMachacek, Joshua
dc.contributor.authorBoadle, Roisin
dc.contributor.authorBuckman, Stephen
dc.contributor.authorSullivan, James
dc.date.accessioned2015-12-08T22:16:19Z
dc.identifier.issn1050-2947
dc.identifier.urihttp://hdl.handle.net/1885/30604
dc.description.abstractRecent 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.
dc.publisherAmerican Physical Society
dc.rightsAuthor/s retain copyright
dc.sourcePhysical Review A: Atomic, Molecular and Optical Physics
dc.subjectKeywords: Energy regions; Experimental evidence; Ground-state helium; Helium atom; Positron scattering; Quasi-bound state; Resonance strengths; Shape resonance; Upper Bound; Binding energy; Electrons; Helium; Resonance; Positrons
dc.titleSearch for positron quasibound states in the doubly excited region of the helium atom
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume86
dc.date.issued2012
local.identifier.absfor020201 - Atomic and Molecular Physics
local.identifier.ariespublicationu4860843xPUB75
local.type.statusPublished Version
local.contributor.affiliationMachacek, Joshua, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationBoadle, Roisin, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationBuckman, Stephen, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationSullivan, James, College of Physical and Mathematical Sciences, ANU
local.bibliographicCitation.issue6
local.bibliographicCitation.startpage3
local.identifier.doi10.1103/PhysRevA.86.064702
local.identifier.absseo970102 - Expanding Knowledge in the Physical Sciences
dc.date.updated2016-02-24T11:25:19Z
local.identifier.scopusID2-s2.0-84870602605
local.identifier.thomsonID000311909800010
dcterms.accessRightsOpen Access
CollectionsANU Research Publications

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