The Adjoint Vacuum Sector of Massless QCD2

TL;DR

This paper studies a specific state in massless two-dimensional QCD with fundamental quarks, exploring its properties, limitations, and connections to fermionic structures within a current-based formulation.

Contribution

It introduces and analyzes the 'one current' state in massless QCD2, highlighting its properties, limitations, and relation to the fermionic structure, especially in the large N_f limit.

Findings

'One current' states are not eigenstates of M^2 except at large N_f.

Infra-red regularization issues are identified.

Connection to fermionic structure is established.

Abstract

We consider a "one current" state, obtained by appication of a color current on the "adjoint" vacuum, in $QCD_2$, with quarks in fundamental representation. The quarks are taken to be massless. The theory on the light-front can be "currentized", namely formulated in terms of currents only. The adjoint vacuum is obtained by applying a current derivative, at zero momentum, on the singlet vacuum. In general the "one current" states are not eigenstates of $M^2=2P^+P^-$, except in the large $N_f$ limit. Problems with infra-red regularizations are pointed out. Connection to fermionic structure is made.