The qq$\bar{\mathbf{q}}$ component in the constituent quark generates the pion cloud of the nucleon

TL;DR

This paper proposes that the pion cloud around nucleons arises from quark-antiquark pairs generated by constituent quarks, explaining spin and flavor asymmetries with quantitative agreement to experimental data.

Contribution

It introduces a model where quark-antiquark pairs coupled to pions form the nucleon's pion cloud, aligning with observed fluctuation probabilities.

Findings

Approximately 30% probability of quark-antiquark pairs around constituent quarks.

About 25% of these pairs manifest as pions in nucleon fluctuation processes.

Model predictions agree with experimental measurements of nucleon pion fluctuations.

Abstract

The spin properties and the flavor asymmetric sea of the nucleon can be well explained by assuming that each constituent quark is surrounded with about 30% probability by a quark-antiquark pair coupled to the pion quantum numbers. We show that about one quarter of these quark-antiquark pairs show up as the pion in $\p\to\n\pi^+$ and $\p\to\p\pi^0$ fluctuation in agreement with the observed value in the ($\e+\p\to\e+$ forward neutron+X) experiment.