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The (e, e’K+) reaction experiments with several nuclear targets performed recently at the Jefferson laboratory have provided high-resolution spectroscopic data. Among others, the 10B(e, e’K+) 10ΛBe reaction data are particularly interesting due to new appearance of extra sub-peaks which seem difficult to be explained within the conventional model with the p-shell nuclear naturalparity configurations. To describe this novel hypernuclear structure, we have extended the model space by introducing the new configurations which include unnatural-parity nuclear core-excited states. This configuration mixing successfully explains the sub-peaks in the 10B(e, e’K+) reaction data. For adjacent hypernuclei with A = 9–11, we show the DWIA spectra of (K−, π−), (π+, K+) and (γ, K+) reactions that are calculated within the extended model in a consistent way. We discuss the theoretical spectra of 9,10ΛBe and 11ΛB production reactions.

The hyperon puzzle, the observation that the two-solar-mass neutron star existence is hardly explained by all models predicting the appearance of hyperons in the neutron star core, is currently one of the unsolved key issues in the physics of compact stars. To solve the hyperon puzzle an experimental program has been proposed by the Jefferson lab hypernuclear collaboration and approved by the Jefferson Lab (JLab) PAC. This program consists in the study of the reaction (e, e’K) on 40Ca and 48Ca nuclei, aimed at investigating the isospin dependence of hyperon dynamics, and in the study of the reaction (e, e’K) on 208Pb nucleus, which is the subject of this paper and which will take advantage of the fact that 208Pb properties largely reflects those of the uniform nuclear matter present in the interior of the neutron stars making it the ideal tool to investigate neutron star features. The proposal of the study of the reaction (e, e’K) on 208Pb was approved by the Jlab PAC in 2020.