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arXiv · 0707.3389

In-medium chiral SU(3) dynamics and hypernuclear structure

P. Finelli·N. Kaiser·D. Vretenar·W. Weise
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Abstract

A previously introduced relativistic energy density functional, successfully applied to ordinary nuclei, is extended to hypernuclei. The density-dependent mean field and the spin-orbit potential are consistently calculated for a $Λ$ hyperon in the nucleus using the SU(3) extension of in-medium chiral perturbation theory. The leading long range $ΛN$ interaction arises from kaon-exchange and $2π$-exchange with $Σ$ hyperon in the intermediate state. Scalar and vector mean fields reflecting in-medium changes of the quark condensates are constrained by QCD sum rules. The model, applied to oxygen as a test case, describes spectroscopic data in good agreement with experiment. In particular, the smallness of the $Λ$ spin-orbit interaction finds a natural explanation in terms of an almost complete cancellation between scalar-vector background contributions and long-range terms generated by two-pion exchange.

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P. Finelli, N. Kaiser, D. Vretenar, W. Weise. 2007-12-10. In-medium chiral SU(3) dynamics and hypernuclear structure. https://doi.org/10.1016/j.physletb.2007.09.070

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