dorsal/arxiv
View SchemaNear threshold rotational excitation of molecular ions by electron-impact
| Authors | A. Faure, V. Kokoouline, Chris H. Greene, Jonathan Tennyson |
|---|---|
| Categories | |
| ArXiv ID | physics/0608078 |
| URL | https://arxiv.org/abs/physics/0608078 |
| DOI | 10.1088/0953-4075/39/20/023 |
Abstract
New cross sections for the rotational excitation of H$_3^+$ by electrons are calculated {\it ab initio} at low impact energies. The validity of the adiabatic-nuclei-rotation (ANR) approximation, combined with $R$-matrix wavefunctions, is assessed by comparison with rovibrational quantum defect theory calculations based on the treatment of Kokoouline and Greene ({\it Phys. Rev. A} {\bf 68} 012703 2003). Pure ANR excitation cross sections are shown to be accurate down to threshold, except in the presence of large oscillating Rydberg resonances. These resonances occur for transitions with $\Delta J=1$ and are caused by closed channel effects. A simple analytic formula is derived for averaging the rotational probabilities over such resonances in a 3-channel problem. In accord with the Wigner law for an attractive Coulomb field, rotational excitation cross sections are shown to be large and finite at threshold, with a significant but moderate contribution from closed channels.
{
"annotation_id": "f35ab8b8-79b3-46c5-8b8d-e43516f0bb94",
"date_created": "2026-03-02T18:01:10.318000Z",
"date_modified": "2026-03-02T18:01:10.318000Z",
"file_hash": "5fd1c0d82865cafd7addc596f167f91004934f992e11a2c66b0507b8f8cbcd40",
"private": false,
"record": {
"abstract": "New cross sections for the rotational excitation of H$_3^+$ by electrons are\ncalculated {\\it ab initio} at low impact energies. The validity of the\nadiabatic-nuclei-rotation (ANR) approximation, combined with $R$-matrix\nwavefunctions, is assessed by comparison with rovibrational quantum defect\ntheory calculations based on the treatment of Kokoouline and Greene ({\\it Phys.\nRev. A} {\\bf 68} 012703 2003). Pure ANR excitation cross sections are shown to\nbe accurate down to threshold, except in the presence of large oscillating\nRydberg resonances. These resonances occur for transitions with $\\Delta J=1$\nand are caused by closed channel effects. A simple analytic formula is derived\nfor averaging the rotational probabilities over such resonances in a 3-channel\nproblem. In accord with the Wigner law for an attractive Coulomb field,\nrotational excitation cross sections are shown to be large and finite at\nthreshold, with a significant but moderate contribution from closed channels.",
"arxiv_id": "physics/0608078",
"authors": [
"A. Faure",
"V. Kokoouline",
"Chris H. Greene",
"Jonathan Tennyson"
],
"categories": [
"physics.atom-ph"
],
"doi": "10.1088/0953-4075/39/20/023",
"title": "Near threshold rotational excitation of molecular ions by electron-impact",
"url": "https://arxiv.org/abs/physics/0608078"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "50b87746-18a6-4f14-bbc8-5535a255a740",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}