Strangeness S =-2 baryon-baryon interactions and femtoscopic correlation functions in covariant chiral effective field theory

We study the baryon-baryon interactions with strangeness S = -2 and corresponding momentum correlation functions in leading order covariant chiral effective field theory. The relevant low energy constants are determined by fitting to the latest HAL QCD simulations, taking into account all the coupled channels. Extrapolating the so-obtained strong interactions to the physical point and considering both quantum statistical effects and the Coulomb interaction, we calculate the and correlation functions with a spherical Gaussian source and compare lambda lambda and (SIC) - p them with recent experimental data. We find a good agreement between our predictions and the experimental measurements by using the source radius determined in proton-proton correlations, which demonstrates the consistency between theory, experiment, and lattice QCD simulations. Moreover, we predict the sigma(+)sigma, sigma(+)lambda , and sigma(+)sigma(-) interactions and corresponding momentum correlation functions. We further investigate the influence of the source shape and size of the hadron pair on the correlation functions studied and show that the current data are not very sensitive to the source shape. Future experimental measurements of the predicted momentum correlation functions will provide a non-trivial test of not only SU(3) flavor symmetry and its breaking but also the baryon-baryon interactions derived in covariant chiral effective field theory.

Automated summary

We study baryon-baryon interactions with strangeness S = -2 using leading order covariant chiral effective field theory. We determine the relevant low energy constants by fitting to the latest HAL QCD simulations, considering all coupled channels. Comparing our calculations with experimental data for lambda lambda and (Σ0Λ)-p correlation functions, we find good agreement which demonstrates consistency between theory, experiment, and lattice QCD simulations. We also predict sigma(+)sigma, sigma(+)lambda, and sigma(+)sigma(-) interactions and their momentum correlation functions.