Universal critical dynamics near the chiral phase transition and the QCD critical point
Yunxin Ye, Johannes V. Roth, Sören Schlichting, Lorenz von Smekal
Published: 2025/9/30
Abstract
We use a novel real-time formulation of the functional renormalization group (FRG) for dynamical systems with reversible mode couplings to study Model G and H, which are the conjectured dynamic universality classes of the two-flavor chiral phase transition and the QCD critical point, respectively. We compute the dynamic critical exponent in both models in spatial dimensions $2<d<4$. We discuss qualitative commonalities and differences in the non-perturbative RG flow, such as weak scaling relations which hold in either case versus the characteristic strong scaling of Model G which is absent in Model H. For Model G, we also extract a novel dynamic scaling function that describes the universal momentum and temperature dependence of the diffusion coefficient of iso-(axial-)vector charges in the symmetric phase.