A Study of the Kaon from the Basis Light-Front Quantization Approach

We study the properties of the kaon through the light-front wave function(LFWF) obtained from the Basis Light-front Quantization(BLFQ) approach. Our Hamiltonian contains the kinetic energy terms, a transverse confining potential motivated by the light-front holographic quantum chromodynamics(LFHQCD) model, a complementary longitudinal confining potential, and the quark-gluon interactions based on quantum chromodynamics (QCD). Our basis space includes the lowest two Fock sectors. Based on the previous work, we tune the only additional strange quark mass parameter to match the resulting kaon mass with the experimental data. Based on the obtained leading Fock sector LFWF, we calculate the parton distribution amplitude(PDA) of the kaon which is in reasonable agreement with the one calculated from perturbative QCD in the massless quark limit. The obtained kaon form factor (FF) agrees with results from the Super Proton Synchrotron(SPS) experiment at the European Organization for Nuclear Research (CERN) and the Fermi National Accelerator Laboratory(FNAL) experiment. The electromagnetic radius (at the leading order Fock sector) is comparable to the one from the particle data group(PDG). In addition, the kaon parton distribution function(PDF), after QCD evolution, can be used to calculate the ratio of the kaon up quark PDF to that of the pion whose trend qualitatively agrees with that of the CERN-NA-003 experimental data. The obtained kaon PDF shows that the ratio between longitudinal momentum fractions of valence quarks, \langle x_uv\rangle/\langle x_sv\rangle , is around 2/3, which agrees with results from the Bethe-Salpeter equation(BSE) model and the lattice QCD calculation in the Michigan State University(MSULat). We also calculate the structure function of the kaon which shows disagreement with the one from BLFQ-NJL calculation. This disagreement would be investigated in the future Electron-Ion Collider experiment(EIC).