Low-energy hypernuclear spectra within a microscopic particle-rotor model with a relativistic point-coupling hyperon-nucleon interaction

We extend the microscopic particle-rotor model for hypernuclear low-lying states by including the derivative and tensor coupling terms in the point-coupling nucleon Λ-particle (NΛ) interaction. Taking CΛ13 as an example, we show that a good overall description for excitation spectra is achieved with four sets of effective NΛ interactions. We find that the Λ hyperon binding energy decreases monotonically with increasing strengths of the high-order interaction terms. In particular, the tensor coupling term decreases the energy splitting between the first 1/2- and 3/2- states and increases the energy splitting between the first 3/2+ and 5/2+ states in CΛ13.