Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

The analytic structure of the QCD propagators, confinement, and deconfinement

Giorgio Comitini

Abstract

We present the first complete calculation of the analytic structure of the zero-spatial-momentum finite-temperature Landau-gauge gluon propagator carried out at one loop by a massive deformation of QCD perturbation theory -- the screened massive expansion -- at temperatures ranging from $T=0$ to $T\approx 3T_{c}$. We find no signatures of deconfinement in the form of meaningful changes in said structure. We argue that, beyond Euclidean space, massive perturbative methods -- including the Curci-Ferrari model -- might be missing crucial dynamical information as a consequence of the perturbative violation of QCD's Ward identities.

The analytic structure of the QCD propagators, confinement, and deconfinement

Abstract

We present the first complete calculation of the analytic structure of the zero-spatial-momentum finite-temperature Landau-gauge gluon propagator carried out at one loop by a massive deformation of QCD perturbation theory -- the screened massive expansion -- at temperatures ranging from to . We find no signatures of deconfinement in the form of meaningful changes in said structure. We argue that, beyond Euclidean space, massive perturbative methods -- including the Curci-Ferrari model -- might be missing crucial dynamical information as a consequence of the perturbative violation of QCD's Ward identities.

Paper Structure

This paper contains 4 sections, 3 equations, 3 figures.

Table of Contents

  1. Introduction
  2. The analytic structure of the gluon propagator at finite $T$
  3. Complex-conjugate poles, the plasmon puzzle and QCD's Ward identities
  4. Conclusions

Figures (3)

  • Figure 1: Real and imaginary part $\varepsilon_{0}(T)$ and $\gamma_{0}(T)$ of the poles of the finite-temperature Landau-gauge gluon propagator in pure Yang-Mills theory (left) and full QCD (right), as a function of temperature. Top: free parameters from the optimization of the screened expansion at $T=0$. Bottom: free parameters from the lattice data. $n_{F}=2+1$ on the top right, $n_{F}=2$ on the bottom right.
  • Figure 2: Spectral function of the finite-temperature Landau-gauge gluon propagator. Order of plots as in Fig. \ref{['Fig:poles']}. The vertical dashed lines and grey bands represent the onset of gluon and quark mass thresholds.
  • Figure 3: For $gT\gg m$ and $g\ll1$, the zero-temperature complex-conjugate poles of the screened massive expansion (SME) become the complex-conjugate poles of ordinary thermal perturbation theory's (oTPT) plasmon puzzle.