Diffractive Vector-Meson Production from the Light-Front Quark Model

ଲେଖକ: S. Puhan
ପ୍ରକାଶିତ: e-Print: 2609.39647 [hep-ph]

arXiv:2609.39647 · INSPIRE-HEP record

ସାରାଂଶ

We study exclusive diffractive electroproduction of the ρ^0, ϕ, J/ψ, and ψ(2S) mesons in the color-dipole picture using two spin-orbit light-front wave functions, S-1 and S-2. S-1 follows from the Melosh--Wigner rotation in the light-front quark model (LFQM), while S-2 is the spin-improved form commonly used in holographic and boosted-Gaussian approaches. Both share the same radial wave function, with their parameters determined from the LFQM Hamiltonian. The color-glass-condensate dipole parameters are fixed from inclusive structure-function data, with no fit to diffractive data. We compare the predictions with measurements of cross sections, R=σ_L/σ_T, t and W dependences, and σ_ϕ/σ_ρ. S-1 gives a better description of the light-meson observables, while S-2 provides a better description of the charmonium ratio σ_ψ(2S)/σ_J/ψ and the J/ψ decay constant. We also present the charge, magnetic, and quadrupole form factors of the four mesons and compare them with available lattice-QCD results