The effect of charm quark on the QCD chiral phase diagram

TL;DR

This paper investigates how including charm quark dynamics affects the QCD phase diagram, revealing a moderate shift in the critical endpoint's location, emphasizing the importance of heavy-flavor effects in QCD phase structure studies.

Contribution

It introduces a novel analysis of charm quark effects on the QCD phase diagram using the miniDSE Dyson-Schwinger scheme, highlighting their subtle influence.

Findings

Charm quark shifts the CEP by 2-3% towards lower chemical potential.

Heavy-flavor dynamics have a noticeable impact on the QCD phase structure.

The study emphasizes including charm quark effects in QCD phase searches.

Abstract

We study the influence of charm quark dynamics on the chiral phase structure of Quantum Chromodynamics (QCD) using the recently developed miniDSE scheme of the Dyson-Schwinger equations. By calculating the quark propagator in $2+1$ and $2+1+1$ flavor QCD, we quantify the impact of including the charm quark as a dynamical degree of freedom on the QCD phase diagram. Our results show that the charm quark induces a moderate but noticeable shift to lower chemical potential in the location of the critical endpoint (CEP) by approximately 2-3%. The result in this work indicates that the heavy-flavor dynamics can subtly influence the QCD phase structure and should be taken into account in particular for searching the CEP of QCD.