Λ hypernuclear potentials beyond linear density dependence

In a recent paper [PLB 837 (2023) 137669] we showed that all measured (1s_Λ, 1p_Λ) pairs of Λ binding energies in Λ-hypernuclei across the periodic table, 12≤A≤208, can be obtained from a Λ-nucleus optical potential with only two adjustable ΛN and ΛNN parameters, associated with leading linear and quadratic terms in the nuclear density, derived by fitting _Λ¹⁶N binding energies. Here we extend the previous analysis by performing least-squares fits to the full set of data points. Consequences of suppressing ΛNN interactions between ‘core’ nucleons and ‘excess’ neutrons are studied and related predictions are made for (1s_Λ, 1p_Λ) binding energies in _Λ^40,48K, obtainable from upcoming ^40,48Ca(e,e^′K⁺) JLab experiments. We find Λ-nucleus partial potential depths of D_Λ⁽²⁾=−38.6±0.8 MeV (ΛN) and D_Λ⁽³⁾=11.3±1.4 MeV (ΛNN), with a total depth D_Λ=−27.3±0.6 MeV at nuclear-matter density ρ₀=0.17 fm⁻³, consistently with our previous results. Extrapolation to higher nuclear densities and possible relevance to the ‘hyperon puzzle’ in neutron-star matter are discussed.