Abstract
We discuss the QCD phase structure at finite temperature and chemical potential for 2-flavor and $2+1$-flavor QCD. The results are achieved by computing QCD correlation functions within a generalized functional approach that combines Dyson-Schwinger equations (DSE) and the functional renormalization group (fRG). In this setup fRG precision data from [A. K. Cyrol, M. Mitter, J. M. Pawlowski, and N. Strodthoff, Phys. Rev. D 97, 054006 (2018).] for the vacuum quark-gluon vertex and gluon propagator of 2-flavor QCD used as input, and the respective DSEs are expanded about this input. While the vacuum results for other correlation functions serve as a self-consistency check for functional approaches, the results at finite temperature and density are computed, for the first time, without the need of phenomenological infrared parameters.
Highlights
A detailed understanding of the QCD phase structure at finite temperature and density are essential for our understanding of the formation of matter and the evolution of the Universe
D 97, 054006 (2018).] for the vacuum quark-gluon vertex and gluon propagator of 2-flavor QCD used as input, and the respective Dyson-Schwinger equations (DSE) are expanded about this input
These correlation functions carry the full information about confinement and chiral symmetry breaking, and their quantitative computation within functional methods has been the subject of many works in the past two decades; for functional renormalization group (fRG) works see e.g., [11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26] and for DSE works see e.g., [8,9,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44]
Summary
While a quantitative access to the gluon propagator in Yang-Mills theory without any phenomenological input requires very elaborate approximations, see [20], its modification in the presence of dynamical quarks converge already in rough approximations to the matter fluctuations: the dominating effect of the matter fluctuations by far is the change in the momentum scale running in the ultraviolet which is already captured very well by perturbation theory This property is reflected in the fact that the gluon propagator does not change significantly if changing the pion mass from the chiral limit to masses of about 400 MeV; see [11]. Note that this approximate decoupling or rather separation of fluctuations changes in the chiral limit with a vanishing strange quark mass In combination this provides us with an optimized expansion scheme of DSEs for QCD, based on the quantitative fRG results in [11]: All correlation functions except the quark propagator are expanded about the 2-flavor case.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
