Parton Distribution Functions from a Light Front Hamiltonian and QCD Evolution for Light Mesons

Area of Science:

• High Energy Physics
• Quantum Chromodynamics
• Particle Physics

Background:

• Parton distribution functions (PDFs) are crucial for understanding hadron structure.
• Accurate PDFs are essential for interpreting high-energy scattering experiments.
• Previous models often struggled with low-momentum scale applications.

Purpose of the Study:

• To derive pion and kaon parton distribution functions from first principles.
• To validate the derived PDFs against experimental data.
• To apply the derived PDFs to predict Drell-Yan cross sections.

Main Methods:

• Utilized a light front effective Hamiltonian in a constituent quark-antiquark representation.
• Employed QCD evolution to obtain valence quark distribution functions.
• Incorporated nucleon PDFs to calculate Drell-Yan cross sections.

Main Results:

• Pion valence quark PDFs are consistent with FNAL-E615 data after QCD evolution.
• The ratio of kaon to pion up quark distributions agrees with CERN-NA3 data.
• Calculated Drell-Yan cross sections match experimental observations.

Conclusions:

• The light front effective Hamiltonian provides accurate PDFs for pions and kaons at low momentum scales.
• The model successfully reproduces key experimental results, validating its predictive power.
• This approach offers a robust framework for studying hadron structure and interactions.