Five-quark components in baryons

TL;DR

This paper discusses the evidence for five-quark components in baryons, explaining various phenomena and proposing a new baryon state, with implications for understanding baryon structure and spectrum.

Contribution

It introduces the concept of five-quark components in baryons and suggests a breathing mode between three-quark and five-quark states, proposing a new baryon resonance.

Findings

Evidence for five-quark components in baryons

Explanation of the $ar d$ over $ar u$ asymmetry

Prediction of a new $ ext{Σ}^*(1/2^-)$ resonance around 1380 MeV

Abstract

Evidence has been accumulating for the existence of significant intrinsic non-perturbative five-quark components in various baryons. The inclusion of the five-quark components gives a natural explanation of the excess of $\bar d$ over $\bar u$, significant quark orbital angular momentum in the proton, the problematic mass and decay pattern of the lowest $1/2^-$ baryon nonet, etc.. A breathing mode of $qqq\leftrightarrow qqqq\bar q$ is suggested for the lowest $1/2^-$ baryon octet. Evidence of a predicted member of the new scheme, $\Sigma^*(1/2^-)$ around 1380 MeV, is introduced.