arXiv:nucl-th/9703049·v2·Nuclear Theory

The effects of varying the strengths of tensor and spin-orbit interactions on M1 and E2 rates in ^{12}C: Comparison of results in $Δ N = 0$ and $Δ N = 0 + 2ℏ ω$ spaces}

M. S. Fayache (Faculté des Sciences de Tunis)🇹🇳 · Y. Y. Sharon🇺🇸 · L. Zamick (Rutgers University)🇺🇸

The energies and transition rates to $J = 1^{+} T = 1$ and $J = 2^{+} T = 0, 1$ states in ^{12}C with matrix elements fitted to realistic $G$ matrix elements obtained in non-relativistic approaches are studied. Then the effects of varying the strengths of the two-body tensor and spin-orbit interactions are also considered. The calculations are done in both a small space (0p) and a large space (0p + $2ℏ ω$ ). In the small space the B(M1) from ground to the $J = 1^{+} T = 1$ is enhanced and gets closer to experiment if the strength of the spin-orbit interaction is increased and/or if that of the tensor interaction is made weaker. In a large space the spin B(M1) gets reduced by almost a factor of two. A `self-weakening' mechanism for the tensor interaction which succeeded in explaining anomalies in other nuclei does not seem to work for this case.

Comments: 9 pages, no figures. Small revisions, new subsection: IIC

The effects of varying the strengths of tensor and spin-orbit interactions on M1 and E2 rates in ^{12}C: Comparison of results in ΔN=0 and ΔN=0+2ℏω spaces}

Abstract

The effects of varying the strengths of tensor and spin-orbit interactions on M1 and E2 rates in ^{12}C: Comparison of results in $Δ N = 0$ and $Δ N = 0 + 2ℏ ω$ spaces}