arXiv:nucl-th/0407039·v1·Nuclear Theory
Spin-orbit splitting of 9 Lambda Be excited states studied with the SU_6 quark-model baryon-baryon interactions
Y. Fujiwara (1) · M. Kohno (2) · K. Miyagawa (3) · Y. Suzuki (4) ((1) Kyoto University · (2) Kyushu Dental College · (3) Okayama Science University · (4) Niigata University)
Abstract
The previous Faddeev calculation of the two-alpha plus Lambda system for 9 Lambda Be is extended to incorporate the spin-orbit components of the SU_6 quark-model baryon-baryon interactions. We employ the Born kernel of the quark-model Lambda N LS interaction, and generate the spin-orbit component of the Lambda alpha potential by the alpha-cluster folding. The Faddeev calculation in the jj-coupling scheme implies that the direct use of the quark-model Born kernel for the Lambda N LS component is not good enough to reproduce the small experimental value Delta E^exp_{ls}=43 +- 5 keV for the 5/2^+ - 3/2^+ splitting. This procedure predicts three to five times larger values in the model FSS and fss2. The spin-orbit contribution from the effective meson-exchange potentials in fss2 is argued to be unfavorable to the small ls splitting, through the analysis of the Scheerbaum factors for the single-particle spin-orbit potentials calculated in the G-matrix formalism.
Comments: 4 pages, 1 figure