Proton structure from a light-front Hamiltonian

TL;DR

This paper derives proton electromagnetic and axial form factors, as well as parton distribution functions, from a light-front Hamiltonian, achieving good agreement with experimental data and global QCD analyses.

Contribution

It introduces a light-front Hamiltonian approach to compute proton structure functions and form factors, aligning well with experimental and global analysis results.

Findings

Electromagnetic and axial form factors match experimental data.

Parton distributions are consistent with global QCD analyses after evolution.

Tensor charge agrees with experimental data, axial charge is slightly outside error bars.

Abstract

We obtain the electromagnetic form factors, the axial form factor, and the parton distribution functions of the proton from the eigenstates of a light-front effective Hamiltonian in the leading Fock representation suitable for low-momentum scale applications. The electromagnetic and the axial form factors are found to be in agreement with the available experimental data. The unpolarized, the helicity, and the transversity valence quark distributions, after QCD evolution, are consistent with the global QCD analyses. The tensor charge also agree the experimental data, while the axial charge is somewhat outside the experimental error bar.