Towards a Hamiltonian first principle approach for nucleon in light-front frame

Basis Light-Front Quantization (BLFQ) is a fully relativistic and nonperturbative approach that formulates Quantum Chromodynamics (QCD) in terms of a light-front quantized Hamiltonian. It holds the potential to realize first-principles calculations of hadronic structures. In previous studies, BLFQ has demonstrated good agreement with global fits and experimental data when using effective Hamiltonians.

Recent advancements in BLFQ include the expansion of Fock space to six-particle sectors, such as five quarks plus one dynamic gluon, and three valence quarks dressed with three gluons. These developments have enabled the implementation of the full light-front QCD Hamiltonian in practical computations.

Using the light-front wave functions generated by BLFQ, we have calculated observables such as the parton distribution functions (PDFs) of gluons and sea quarks at low-resolution scales. These results have been evolved using QCD evolution equations to higher energy scales for direct comparison with experimental data.

As a result, BLFQ allows for predictions of the gluon and sea quark spin contributions to the proton spin, as well as insights into the proton’s three-dimensional structure at the parton level.