dorsal/arxiv
View SchemaLarge Shell Model Calculations for Calcium Isotopes: Spectral Statistics and Chaos
| Authors | V. R. Manfredi, J. M. G. Gomez, L. Salasnich |
|---|---|
| Categories | |
| ArXiv ID | nucl-th/9805049 |
| URL | https://arxiv.org/abs/nucl-th/9805049 |
Abstract
We perform large shell model calculations for Calcium isotopes in the full fp shell by using the realistic Kuo-Brown interaction. The Calcium isotopes are especially interesting because the nearest-neighbour spacing distribution P(s) of low-lying energy levels shows significant deviations from the predictions of the Gaussian Orthogonal Ensemble of random--matrix theory. This contrasts with other neighbouring nuclei which show fully chaotic spectral distributions. We study the chaotic behaviour as a function of the excitation energy. In addition, a clear signature of chaos suppression is obtained when the single-particle spacings are increased. In our opinion the relatively weak strength of the neutron-neutron interaction is unable to destroy the regular single-particle mean-field motion completely. In the neighbouring nuclei with both protons and neutrons in valence orbits, on the other hand, the stronger proton-neutron interaction would appear to be sufficient to destroy the regular mean-field motion.
{
"annotation_id": "0fe2e4fb-91d8-486f-b936-8d35bf52696b",
"date_created": "2026-03-02T18:00:21.714000Z",
"date_modified": "2026-03-02T18:00:21.714000Z",
"file_hash": "a49d3f83255a7c08af641ae10314f9002545db97e056448b0efe080ebc37f638",
"private": false,
"record": {
"abstract": "We perform large shell model calculations for Calcium isotopes in the full fp\nshell by using the realistic Kuo-Brown interaction. The Calcium isotopes are\nespecially interesting because the nearest-neighbour spacing distribution P(s)\nof low-lying energy levels shows significant deviations from the predictions of\nthe Gaussian Orthogonal Ensemble of random--matrix theory. This contrasts with\nother neighbouring nuclei which show fully chaotic spectral distributions. We\nstudy the chaotic behaviour as a function of the excitation energy. In\naddition, a clear signature of chaos suppression is obtained when the\nsingle-particle spacings are increased. In our opinion the relatively weak\nstrength of the neutron-neutron interaction is unable to destroy the regular\nsingle-particle mean-field motion completely. In the neighbouring nuclei with\nboth protons and neutrons in valence orbits, on the other hand, the stronger\nproton-neutron interaction would appear to be sufficient to destroy the regular\nmean-field motion.",
"arxiv_id": "nucl-th/9805049",
"authors": [
"V. R. Manfredi",
"J. M. G. Gomez",
"L. Salasnich"
],
"categories": [
"nucl-th"
],
"title": "Large Shell Model Calculations for Calcium Isotopes: Spectral Statistics and Chaos",
"url": "https://arxiv.org/abs/nucl-th/9805049"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "a34ee16f-d30a-4245-97df-fb07f6144465",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}