Flavor symmetry breaking in the $\Delta$ sea

TL;DR

This paper proposes a novel test to verify if chiral symmetry causes the observed flavor asymmetry in the proton's sea quarks by comparing it with the $ar d-ar u$ content in the $ riangle^+$ baryon, leveraging recent lattice QCD advances.

Contribution

It introduces a new experimental approach to test the role of chiral symmetry in sea quark flavor asymmetry using $ riangle^+$ baryon data.

Findings

Anticipates a significant $ar d-ar u$ enhancement in $ riangle^+$ near the $N ext{pi}$ decay threshold.

Suggests lattice QCD can soon test the proposed flavor asymmetry comparison.

Provides a new perspective on chiral symmetry's role in hadron structure.

Abstract

The discovery of a sizeable asymmetry in the $\bar u$ and $\bar d$ distributions in the proton was one of the more consequential experimental findings in hadron physics last century. Although widely believed to be related to the fundamental role of chiral symmetry in QCD, a definitive verification of this hypothesis has remained elusive. We propose a novel test of the role of chiral symmetry in generating the sea flavor asymmetry by comparing the $\bar d-\bar u$ content in the proton with that in the $\Delta^+$ baryon, where a significant enhancement is expected around the opening of the $N \pi$ decay channel. Recent developments in lattice QCD suggest a promising way to test this prediction in the near future.