Chirality distributions inside baryons in ${\rm QCD_2}$

TL;DR

This paper investigates the distribution of chirality within baryons in two-dimensional QCD, revealing a topologically driven concentration near zero momentum fraction, contrasting with mesons, and discusses implications for higher-dimensional QCD and experiments.

Contribution

It demonstrates how the topological structure of baryons in 2D QCD influences their internal chirality distribution, a novel insight linking topology and spin structure.

Findings

Chirality in baryons concentrates near zero momentum fraction.

Chirality distribution in mesons vanishes at small x.

Topological features determine the constituent structure of baryons.

Abstract

The connection between the spin distribution and the topological structure of the baryon is an open and important problem. Here we address it using QCD in $(1+1)$ spacetime dimensions, which is exactly solvable at large number of colors $N$. It is found that the distribution of chirality inside a baryon is drastically different from a chirality distribution inside states with zero baryon number, ``mesons". This difference is shown to arise from the topological structure of the baryon -- at large $N$, all of the baryon's chirality is concentrated near $x=0$, whereas in a meson state it vanishes in the small $x$ limit. Our results illustrate how the constituent features of the baryon reemerge and are tied to the topological features of the bosonized solitonic solution. Possible implications for QCD in $(3+1)$ dimensions and for deep inelastic scattering experiments are discussed.