Low-energy positron scattering from metastable helium
Abstract
Low-energy positron scattering from singlet and triplet metastable He(1s2s) is investigated using the R-matrix propagation method in hyperspherical coordinates. Elastic and positronium-formation cross sections are reported, and near-threshold resonance structures are analyzed in terms of eigenphase sums and the time-delay matrix. For the triplet target, the calculated cross sections are in agreement with available convergent-close-coupling results and display the expected threshold behavior. Beyond the known S-wave features, Feshbach resonance series in higher partial waves extending up to highly excited atomic thresholds are systematically identified. The time-delay matrix further uncovers hidden resonances that produce obvious structures in the positronium-formation cross sections.
Versions
Related
- Interactions and dynamics of metastable triplet-state helium dimer with Ne and Ar
- Coherent deeply virtual Compton scattering on helium-4 beyond the leading twist approximation
- The Effective Phonon Frequency and Mass Involved in Electron-Phonon Coupling at Metal Surfaces from Helium Atom Scattering.
- Electron Scattering with ASTRA: Helium and Molecular Hydrogen
- Helium Atom Scattering from Cold Salty Water: Impact of Microscopic and Mesoscopic Surface Structure
BibTeX
@misc{gao2026lowenergy,
title = {{Low-energy positron scattering from metastable helium}},
author = {Ning-Ning Gao and Hui-Li Han and Ting-Yun Shi and Li-Yan Tang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2606.29253},
eprint = {2606.29253},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.29253},
}
RIS
TY - UNPB
TI - Low-energy positron scattering from metastable helium
AU - Ning-Ning Gao
AU - Hui-Li Han
AU - Ting-Yun Shi
AU - Li-Yan Tang
PY - 2026
DA - 2026/09/18
PB - arXiv
DO - 10.48550/arxiv.2606.29253
UR - https://arxiv.org/abs/2606.29253
AB - Low-energy positron scattering from singlet and triplet metastable He(1s2s) is investigated using the R-matrix propagation method in hyperspherical coordinates. Elastic and positronium-formation cross sections are reported, and near-threshold resonance structures are analyzed in terms of eigenphase sums and the time-delay matrix. For the triplet target, the calculated cross sections are in agreement with available convergent-close-coupling results and display the expected threshold behavior. Beyond the known S-wave features, Feshbach resonance series in higher partial waves extending up to highly excited atomic thresholds are systematically identified. The time-delay matrix further uncovers hidden resonances that produce obvious structures in the positronium-formation cross sections.
ER -