Perturbative and Non-Perturbative Origins of the Proton Sea

TL;DR

This paper presents a hybrid model combining perturbative and non-perturbative effects to explain the flavor asymmetry in the proton sea, validated against Fermilab E866 data and extending to higher x with future experiments.

Contribution

It introduces a novel hybrid model incorporating meson cloud formalism and statistical perturbative processes to better describe the proton sea asymmetry.

Findings

The model successfully reproduces the E866 data on dbar/ubar ratio.

It predicts the kinematic dependence of the ratio at higher x.

The approach bridges perturbative and non-perturbative QCD effects in proton structure.

Abstract

Deep Inelastic Scattering and Drell-Yan experiments have measured a light flavor asymmetry in the proton sea. The excess of dbar over ubar quarks can be understood in many models, but the ratio dbar(x)/ubar(x) measured by Fermilab E866 has not been successfully described. Fermilab E-906 will probe the kinematic dependence of this ratio with better resolution and extend it to higher x. We have developed a hybrid model that includes both perturbative and non-perturbative contributions to the proton sea. A meson cloud formalism is used to represent the non-perturbative fluctuation of the proton into meson-baryon states. We include perturbative processes by using a statistical model that uses Fock states of quarks, antiquarks and gluons to represent the parton distributions of the 'bare' hadrons in the meson cloud. We compare our results to the E866 data.