dorsal/arxiv
View SchemaEffects of the Spin-Orbit and Tensor Interactions on the $M1$ and $E2$ Excitations in Light Nuclei
| Authors | M. S. Fayache, Y. Y. Sharon, L. Zamick, P. von Neumann-Cosel, A. Richter |
|---|---|
| Categories | |
| ArXiv ID | nucl-th/9604003 |
| URL | https://arxiv.org/abs/nucl-th/9604003 |
| DOI | 10.1016/S0375-9474(97)00403-X |
Abstract
The effects of varying the spin-orbit and tensor components of a realistic interaction on $M1$ excitation rates and $B(E2)'s$ are studied on nuclei in the $0p$ and $1s-0d$ shells. Not only the total $M1$ but also the spin and orbital parts separately are studied. The single-particle energies are first calculated with the same interaction that is used between the valence nucleons. Later this stringent condition is relaxed somewhat and the $1s$ level is raised relative to $0d$. For nuclei up to $^{28}Si$, much better results i.e stronger $B(M1)$ rates are obtained by increasing the strength of the spin-orbit interaction relative to the free value. This is probably also true for $^{32}S$, but $^{36}Ar$ presents some difficulties. The effects of weakening the tensor interaction are also studied. On a more subtle level, the optimum spin-orbit interaction in the lower half of the $s-d$ shell, as far as $M1$ excitations are concerned, is substantially larger than the difference $E(J=3/2^+)_1-E(J=5/2^+)_1=5.2~MeV$ in $^{17}O$. A larger spin-orbit splitting is also needed to destroy the triaxiality in $^{22}Ne$. Also studied are how much $M1$ orbital and spin strength lies in an observable region and how much is buried in the grass at higher energies. It is noted that for many nuclei the sum $B(M1)_{orbital}+B(M1)_{spin}$ is very close to $B(M1)_{total}$, indicating that the summed cross terms are very small.
{
"annotation_id": "54f8a129-da0d-430b-b8ab-c9390d23dace",
"date_created": "2026-03-02T18:00:15.307000Z",
"date_modified": "2026-03-02T18:00:15.307000Z",
"file_hash": "e4cddf7d6eb436ef8ce5ce3322fadce31e6bf6a576e0da56176be039db79ef86",
"private": false,
"record": {
"abstract": "The effects of varying the spin-orbit and tensor components of a realistic\ninteraction on $M1$ excitation rates and $B(E2)\u0027s$ are studied on nuclei in the\n$0p$ and $1s-0d$ shells. Not only the total $M1$ but also the spin and orbital\nparts separately are studied. The single-particle energies are first calculated\nwith the same interaction that is used between the valence nucleons. Later this\nstringent condition is relaxed somewhat and the $1s$ level is raised relative\nto $0d$. For nuclei up to $^{28}Si$, much better results i.e stronger $B(M1)$\nrates are obtained by increasing the strength of the spin-orbit interaction\nrelative to the free value. This is probably also true for $^{32}S$, but\n$^{36}Ar$ presents some difficulties. The effects of weakening the tensor\ninteraction are also studied. On a more subtle level, the optimum spin-orbit\ninteraction in the lower half of the $s-d$ shell, as far as $M1$ excitations\nare concerned, is substantially larger than the difference\n$E(J=3/2^+)_1-E(J=5/2^+)_1=5.2~MeV$ in $^{17}O$. A larger spin-orbit splitting\nis also needed to destroy the triaxiality in $^{22}Ne$. Also studied are how\nmuch $M1$ orbital and spin strength lies in an observable region and how much\nis buried in the grass at higher energies. It is noted that for many nuclei the\nsum $B(M1)_{orbital}+B(M1)_{spin}$ is very close to $B(M1)_{total}$, indicating\nthat the summed cross terms are very small.",
"arxiv_id": "nucl-th/9604003",
"authors": [
"M. S. Fayache",
"Y. Y. Sharon",
"L. Zamick",
"P. von Neumann-Cosel",
"A. Richter"
],
"categories": [
"nucl-th"
],
"doi": "10.1016/S0375-9474(97)00403-X",
"title": "Effects of the Spin-Orbit and Tensor Interactions on the $M1$ and $E2$ Excitations in Light Nuclei",
"url": "https://arxiv.org/abs/nucl-th/9604003"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "0ca1e96f-7834-4dd7-89c4-54bc99522633",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}