ΛcN interaction in leading-order covariant chiral effective field theory

We study the ΛcN interaction in the covariant chiral effective field theory (ChEFT) at leading order. All the relevant low-energy constants are determined by fitting to the lattice QCD simulations from the HAL QCD Collaboration. Extrapolating the results to the physical point, we show that the ΛcN interaction is weakly attractive in the S01 channel, but in the S13 channel it is only attractive at extremely low energies and soon turns repulsive for larger laboratory energy. Furthermore, we show that the neglect of the S13-D13 coupling provided by the leading-order covariant ChEFT would result in an attractive interaction in the S13 channel at the physical point, which coincides with the previous nonrelativistic ChEFT study. As a byproduct, we predict the D13 phase shifts and the mixing angel 1, which can be checked by future lattice QCD simulations. In addition, we compare the ΛcN interaction with the ΛN and NN interactions to study how the baryon-nucleon (BN) interactions evolve as a function of the baryon mass with the replacement of a light quark by a strange or charm quark in the baryon (B).