Parton distributions of light quarks and antiquarks in the proton

TL;DR

This paper develops an algebraic model for the proton's wave function, incorporating scalar and pseudovector diquark correlations, to calculate parton distribution functions and explain observed asymmetries and structure functions.

Contribution

It introduces a novel algebraic Ansatz including pseudovector diquarks to accurately model proton parton distributions and explain experimental data.

Findings

Pseudovector diquark component is essential for neutron-proton structure function ratio.

A modest Pauli blocking effect explains the proton's light-quark antimatter asymmetry.

Light-front momentum fractions are similar across parton classes, but higher moments differ from pion distributions.

Abstract

An algebraic Ansatz for the proton's Poincar\'e-covariant wave function, which includes both scalar and pseudovector diquark correlations, is used to calculate proton valence, sea, and glue distribution functions (DFs). Regarding contemporary data, a material pseudovector diquark component in the proton is necessary for an explanation of the neutron-proton structure function ratio; and a modest Pauli blocking effect in the gluon splitting function is sufficient to explain the proton's light-quark antimatter asymmetry. In comparison with pion DFs, the light-front momentum fractions carried by all identifiable parton classes are the same; on the other hand, the higher moments are different. Understanding these features may provide insights that explain distinctions between Nambu-Goldstone bosons and seemingly less complex hadrons.