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

TL;DR

This paper enhances the microscopic particle-rotor model for hypernuclear spectra by incorporating derivative and tensor couplings in the relativistic point-coupling hyperon-nucleon interaction, improving spectral descriptions.

Contribution

It introduces derivative and tensor coupling terms into the model, providing a more accurate description of hypernuclear low-lying states and spectra.

Findings

Good agreement with experimental spectra using four effective interactions

Tensor coupling influences energy splittings between specific hypernuclear states

Hyperon binding energy decreases with stronger high-order interaction terms

Abstract

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-$\Lambda$ particle ($N\Lambda$) interaction. Taking $^{13}_{~\Lambda}$C as an example, we show that a good overall description for excitation spectra is achieved with four sets of effective $N\Lambda$ interaction. We find that the $\Lambda$ hyperon binding energy decreases monotonically with increasing the 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 $^{13}_{~\Lambda}$C.