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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 $ΔN = 0 + 2\hbarω$ spaces}

M. S. Fayache·Y. Y. Sharon·L. Zamick
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Abstract

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 + $2\hbarω$). 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.

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M. S. Fayache, Y. Y. Sharon, L. Zamick. 1997-04-17. 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 $ΔN = 0 + 2\hbarω$ spaces}. https://arxiv.org/abs/nucl-th/9703049

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