The other critical point: hydrodynamics and chiral symmetry breaking

Abstract: First we analyze the evolution of hydrodynamic fluctuations for QCD matter below Tc in the chiral limit, where the pions (the Goldstone modes) must be treated as additional superfluid degrees of freedom. In the presence of a finite pion mass, the hydrodynamic theory is ordinary hydrodynamics at long distances, and superfluid-like at short distances. The presence of the superfluid degrees of freedom then gives specific contributions to the bulk viscosity, the shear viscosity, and diffusion coefficients of the ordinary theory at long distances which we compute. This determines, in some cases, the leading dependence of the transport parameters of QCD on the pion mass. We analyze the predictions of this computation, as the system approaches the $O(4) $ critical point.

If time permits I will discuss the computation of the dissipative superfluid parameters in kinetic theory. Specifically, I will compute the axial charge diffusion coefficient and damping rate in chiral perturbation theory which are well defined when the pion mass is small compared to the mean free path.

general relativity and quantum cosmologyHEP - phenomenologyHEP - theorynuclear theory

Audience: researchers in the topic

IGFAE Theory Seminars