Impact of Phi and Sigma-Star Mesons on Neutron Star Properties

Recent research has examined the effects of the phi and sigma-star mesons on the properties of hyperon stars, particularly focusing on the role of Delta resonances. This study utilized the linear Relativistic Mean-Field (RMF) theory to analyze various parameters influencing neutron stars, including particle number distributions, equations of state (EOS), mass-radius relations, and tidal deformabilities.

The authors, Chen Wu and Wenjun Guo, reported that strange mesons emerge at approximately three times the normal nuclear density and significantly lower the critical density of baryons in high-density regions. They also noted that as the coupling parameter between Delta resonances and nucleons increases, the presence of Delta resonances tends to suppress hyperons, effectively shifting the critical density to lower values. This shift is crucial for addressing the so-called 'hyperon puzzle'—a challenge in understanding the composition and behavior of neutron stars.

The study indicates that the early appearance of Delta resonances may be vital for the stability of neutron stars. Additionally, the inclusion of these resonances was found to decrease the radius of neutron stars, which has implications for the understanding of their structure and behavior in astrophysical contexts. The findings also align with observational data from gravitational wave events, such as GW170817, suggesting that the theoretical models presented could enhance the understanding of neutron star properties in relation to astronomical observations.

This research contributes to the ongoing discourse on neutron star physics and may influence future studies aimed at unraveling the complexities of dense nuclear matter. The full paper can be accessed here.