Femtoscopic study of the Λα interaction

We examine the Λ-⁴He (α) momentum correlation in high-energy collisions to elucidate the interaction between Lambdas (Λ) and nucleons (N). We compare phenomenological Λα potentials with different strengths at short range. In addition to the conventional Gaussian-type potentials, we construct the Λα potentials by substituting the nucleon density distribution in α particle into the Skyrme-type Λ potentials. We find that the dependence on the employed potential models is visible in the correlation functions from a small-size source. This indicates that the Λα momentum correlation could constrain the property of the ΛN interaction at high densities, which is expected to play an essential role in dense nuclear matter. Also, we verify that the Lednicky-Lyuboshits formula can yield erroneous results for a small-size source with a potential which has a large interaction range, like the Λα system.