Phenomenological Lambda-Nuclear Interactions

Abstract

Variational Monte Carlo calculations for ${}_{\Lambda }^{4}H$ (ground and excited states) and ${}_{\Lambda }^{5}He$ are performed to decipher information on $\Lambda$-nuclear interactions. Appropriate operatorial nuclear and $\Lambda$-nuclear correlations have been incorporated to minimize the expectation values of the energies. We use the Argonne ${\upsilon }_{18}$ two-body NN along with the Urbana IX three-body NNN interactions. The study demonstrates that a large part of the splitting energy in ${}_{\Lambda }^{4}H$ ($0^{+}-1^{+}$) is due to the three-body $\Lambda$ NN forces. ${}_{\Lambda }^{17}O$ hypernucleus is analyzed using the {\it s}-shell results. $\Lambda$ binding to nuclear matter is calculated within the variational framework using the Fermi-Hypernetted-Chain technique. There is a need to correctly incorporate the three-body $\Lambda$ NN correlations for $\Lambda$ binding to nuclear matter.

Comments: 18 pages (TeX), 2 figures