Search for resonances in the scattering of low-energy positrons from atoms and molecules
James P Sullivan; Steven J Gilbert; Stephen J Buckman; Clifford M Surko; James P Sullivan; Physics Department, University of California, San Diego, Gilman Drive, La Jolla, CA 92093-0319, USA; Steven J Gilbert; Physics Department, University of California, San Diego, Gilman Drive, La Jolla, CA 92093-0319, USA; Stephen J Buckman; Physics Department, University of California, San Diego, Gilman Drive, La Jolla, CA 92093-0319, USA; Clifford M Surko; Physics Department, University of California, San Diego, Gilman Drive, La Jolla, CA 92093-0319, USA
Журнал:
Journal of Physics B: Atomic, Molecular and Optical Physics
Дата:
2001-08-14
Аннотация:
In a search for quasi-bound states, or resonances, high-resolution measurements (ΔE~25 meV) of the total positron scattering cross sections have been carried out in the energy region of the first electronically excited states of H<sub>2</sub>, N<sub>2</sub>, CO and Ar. In the case of H<sub>2</sub>, a recent calculation by Varella et al predicts such a resonance in the total elastic cross section near the excitation threshold for the B <sup>1</sup>Σ<sub>u</sub><sup>+</sup> state. We find no experimental evidence for the existence of this resonance and also find similar negative results for the other atomic and molecular targets.
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