Light sea-quark flavor asymmetry and angular momentum of the nucleon in a scalar-vector spectator model

TL;DR

This paper develops a light-front spectator model for the proton, fitting parameters to experimental data, and predicts sea-quark asymmetry and angular momentum distributions consistent with recent measurements.

Contribution

It introduces a scalar-vector spectator model with dynamic evolution, providing new insights into sea-quark asymmetry and nucleon angular momentum.

Findings

Predicted a sustained  enhancement at high x.

Extended distributions from  to 100 GeV^2.

Achieved excellent agreement with recent SeaQuest measurements.

Abstract

We present a light-front spectator model that describes the proton as an active sea antiquark paired with a composite scalar-vector spectator. Using a spatial profile based on soft-wall AdS/QCD, we fit our initial parameters to CT18NNLO data and Bacchetta-Radici extractions at an initial scale of $\mu_0^2=1.0~\text{GeV}^2$. By allowing these parameters to evolve dynamically, we extend our distributions up to $\mu^2=100~\text{GeV}^2$. We specifically calculate the sea-quark asymmetry at the SeaQuest scale, predicting a sustained $\bar{d}$ enhancement at high $x$ that is in excellent agreement with recent E906 measurements. Additionally, we calculate the leading chiral-even generalized parton distributions (GPDs) and evaluate the total angular momentum carried by the sea quarks, comparing our findings with established results.