Chiral symmetry breaking in Hamiltonian QCD in Coulomb gauge

TL;DR

This paper investigates spontaneous chiral symmetry breaking in Hamiltonian QCD within Coulomb gauge, showing that including quark-gluon coupling enhances low-energy chiral properties and aligns with phenomenological data.

Contribution

It introduces a novel variational ansatz for the quark wave functional that includes quark-gluon coupling, improving the understanding of chiral symmetry breaking in Hamiltonian QCD.

Findings

Quark-gluon coupling significantly increases the quark condensate.

The constituent quark mass is substantially enhanced by the coupling.

Results agree well with phenomenological values.

Abstract

Spontaneous breaking of chiral symmetry is investigated in the Hamiltonian approach to QCD in Coulomb gauge. The quark wave functional is determined by the variational principle using an ansatz which goes beyond the commonly used BCS-type of wave functionals and includes the coupling of the quarks to the transversal spatial gluons. Using the lattice gluon propagator as input it is shown that the low energy chiral properties of the quarks, like the quark condensate and the constituent quark mass, are substantially increased by the coupling of the quarks to the spatial gluons. Our results compare favourably with the phenomenological values.