Hui-wen Zheng | Searcharxiv

arXiv2025

A quantitative analysis of Gravitational Wave spectrum sourced from First-Order Chiral Phase Transition of QCD

We investigate the cosmological first-order chiral phase transition of QCD, and for the first time calculate its parameters which can fully determine the gravitational wave spectrum. With the state-of-the-art calculation from the functional QCD method, we found that the large chemical potential of QCD phase transition results in very weak and fast first-order phase transitions at the temperature lower than $\mathcal{O}(10^2)$ MeV. These results further suggest that the GW signals of NANOGrav are very unlikely sourced from the chiral phase transition of QCD.

hep-ph↗

arXiv2024

The effective potential of composite operator in the first order region of QCD phase transition

We propose a method to determine the effective potential of QCD from the gap equation, by introducing the homotopy method between the solutions of the equation of motion. Via this method, the effective potential beyond the bare vertex approximation is obtained, which then generalizes the Cornwall, Jackiw and Tomboulis (CJT) effective potential for the bilocal composite operators. Moreover, the extended effective potential is set to be a function of self energy instead of the propagator, which is the key point for the potential to be bounded from below. We then investigate the extended effective potential in the cases of phase transition of the QCD vacuum with a small current quark mass, and the first-order phase transition of QCD at finite temperature and high baryon chemical potential. In the former case, the effective potential shows as an inflection point at the critical mass where the multiple solutions of the Dyson-Schwinger equation (DSE) vanishes, which is consistent with that obtained by solving the DSE directly. For the latter case, the in-medium properties, such as the latent heat and the difference of trace anomaly, of QCD is obtained.

hep-ph↗