Lattice QCD Anatomy via the Energy-Momentum Component of Gluons

TL;DR

This paper uses lattice QCD to analyze how different energy-momentum components of gluons contribute to key QCD phenomena like confinement, chiral symmetry breaking, and topological charge, revealing distinct momentum ranges for each.

Contribution

It introduces a momentum cutoff method in lattice QCD to identify specific gluon energy-momentum components responsible for various QCD phenomena, highlighting their differences.

Findings

Color confinement is induced by gluons below 1.5 GeV.

Spontaneous chiral symmetry breaking involves a broad momentum range above 1.5 GeV.

Topological charge is generated by a broad energy-momentum component.

Abstract

In this thesis, we perform the lattice QCD analysis via the energy-momentum component of gluons. By introducing the momentum cutoff to the link variable, we investigate which energy-momentum components of gluons induce each QCD phenomenon. We use the Landau gauge for the most part of the lattice QCD analysis. In lattice QCD, we analyze color confinement, spontaneous chiral symmetry breaking, topological charge, and the related topics. We also discuss several comparisons with effective theories. As for color confinement, we calculate the quark-antiquark potential, the color flux tube, and meson masses. From quantitative analysis, we find that color confinement is induced by the low-momentum component below 1.5 GeV. As for spontaneous chiral symmetry breaking, we calculate the chiral condensate and the Dirac spectrum. Spontaneous chiral symmetry breaking is induced by the broad low-momentum component which ranges even above 1.5 GeV. The present result suggests that color confinement and spontaneous chiral symmetry breaking are induced by somehow different energy-momentum components of gluons. As for topological charge, we calculate the topological charge density and the Dirac zero mode. Topological charge is induced by the broad energy-momentum component, which is similar to spontaneous chiral symmetry breaking.