Description of single-Lambda hypernuclei with relativistic point coupling model

TL;DR

This paper extends a relativistic point coupling model to describe single-$\Lambda$ hypernuclei by adding effective contact interactions and fitting to experimental data, achieving good reproduction of binding energies across various nuclei.

Contribution

The paper introduces a novel extension of the relativistic point coupling model specifically for single-$\Lambda$ hypernuclei, including new $N$-$\Lambda$ contact couplings and parameter fitting.

Findings

Model reproduces experimental $\\Lambda$ binding energies across a wide mass range.

Some interactions predict reversed spin-orbit partner ordering in heavy hypernuclei.

Discussion on the consistency of interactions with quark model predictions.

Abstract

We extend the relativistic point coupling model to single-$\Lambda$ hypernuclei. For this purpose, we add $N$-$\Lambda$ effective contact couplings to the model Lagrangian, and determine the parameters by fitting to the experimental data for $\Lambda$ binding energies. Our model well reproduces the data over a wide range of mass region although some of our interactions yield the reverse ordering of the spin-orbit partners from that of nucleons for heavy hypernuclei. The consistency of the interaction with the quark model predictions is also discussed.