{
  "id": "nucl-th/9604003",
  "version": "v1",
  "published": "1996-04-02T21:30:19.000Z",
  "updated": "1996-04-02T21:30:19.000Z",
  "title": "Effects 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"
  ],
  "comment": "39 pages, revtex 3.0",
  "doi": "10.1016/S0375-9474(97)00403-X",
  "categories": [
    "nucl-th"
  ],
  "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.",
  "revisions": [
    {
      "version": "v1",
      "updated": "1996-04-02T21:30:19.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "tensor interaction",
      "light nuclei",
      "optimum spin-orbit interaction",
      "spin strength lies",
      "orbital parts"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "Elsevier",
      "journal": "Nucl. Phys. A"
    },
    "note": {
      "typesetting": "RevTeX",
      "pages": 39,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 417308
    }
  }
}