Precisely determine ΛN low-energy constants constrained by hypertriton data

Ascertain high-precision values of the low-energy constants for the leading-order S-wave ΛN contact interaction, overcoming the limitation that the large experimental uncertainty in the hypertriton Λ separation energy prevents precise determination using current constraints.

Background

The ΛN interaction is constrained in this work by fitting the unpolarized Λp→Λp cross section and ensuring the hypertriton remains a shallow bound state. However, the empirical Λ separation energy of the hypertriton is not yet known with sufficient precision to tightly constrain the ΛN scattering parameters.

This uncertainty limits the precision of the extracted ΛN low-energy constants, which in turn affects downstream predictions for hypernuclear separation energies and spin-dependent splittings. Improved constraints—either experimental (e.g., better BΛ measurements for the hypertriton) or theoretical—would enable a more precise determination.