Two New Hyperon Coupling Models in the Light of the Massive Neutron Star PSR J0348+0432**Supported by the National Key R&D Program of China under Grant Nos. 2018YFA0404403, 2016YFE0129300; by the National Natural Science Foundation of China under Grant Nos. 11535004, 11761161001, 11375086, 11120101005, 11175085, 11235001, 11565010, and 11881240623; and by the Science and Technology Development Fund of Macau under Grant

Abstract

In the context of the relativistic mean field theory, we propose two new hyperon coupling models, namely the limitation model and the potential well depth model, in the light of the observed data for the massive neutron PSR J0348+0432. The radius of PSR J0348+0432 given by the limitation model is found to be 12.52 km ∼ 12.97 km, while the radius given by the potential well depth model is found to be 12.19 km ∼ 12.89 km. We also calculate the gravitational redshift of PSR J0348+0432 within these two models, for which the limitation model gives 0.346 ∼ 0.391 and the potential well depth model gives 0.350 ∼ 0.409. Further exploration of these two models shows that, these two models are almost degenerate for neutron stars lighter than 1.85 M⊙, and start to give different results for massive neutron stars heavier than 1.85 M⊙. Therefore, the studies of massive neutron stars could be crucial for discriminating these two models and help deepen our understanding of hyper-nuclear interactions.