Unified analysis of screening masses for vector and axial-vector mesons and their diquark partners in the Contact Interaction model

We present a comprehensive study of the screening masses of vector and axial-vector mesons and their corresponding diquark partners within a symmetry-preserving vector-vector contact interaction approach. Our analysis includes mesons and diquarks composed of both light and heavy quarks, providing a unified description of their thermal behavior. The longitudinal and transverse modes of the screening masses are analyzed, and the results are systematically compared with other theoretical approaches. At $T = 0$ MeV, our predictions agree with available experimental data, and a comparison with the expected free theory limit at high temperatures is also presented. Notably, the parity partners of the lightest mesons and diquarks converge at high temperatures, signaling chiral symmetry restoration within this framework. These results provide a consistent and detailed picture of meson and diquark properties at finite temperature and lay the groundwork for extending the capabilities of the model to baryon screening masses in the quark-diquark picture.

💡 Research Summary

The paper presents a comprehensive study of the screening masses of vector (V) and axial‑vector (AV) mesons and their corresponding diquark partners using a symmetry‑preserving vector‑vector contact‑interaction (CI) model. The authors extend previous CI work, which focused mainly on light‑quark pseudoscalar and scalar channels, to include spin‑1 states composed of both light (u, d, s) and heavy (c, b) quarks. The framework is built on a temperature‑dependent gap equation for the dressed quark propagator and a homogeneous Bethe‑Salpeter equation (BSE) solved in the rainbow‑ladder truncation. The gluon propagator is replaced by a momentum‑independent constant, characterized by an infrared coupling α̂_IR and a gluon mass scale m_g = 500 MeV. Infrared (Λ_IR) and ultraviolet (Λ_UV) regulators are introduced; Λ_IR is made temperature‑dependent via Λ_IR(T)=Λ_IR(0)