Polarized gluon distribution in the proton from holographic light-front QCD
Bheemsehan Gurjar, Chandan Mondal, Dipankar Chakrabarti
Abstract
We obtain the gluon parton distribution functions (PDFs) in the proton within the extended light-front holographic QCD framework, where the proton couples with the spin-2 Pomeron in anti--de Sitter space, together with constraints imposed by the Veneziano model. The gluon helicity asymmetry, after satisfying the perturbative QCD constraints at small and large longitudinal momentum regions, agrees with existing experimental measurements. The polarized gluon distribution is consistent with global analyses. We predict the gluon helicity contribution to the proton spin, $\mathrm{\ensuremath{\Delta}}G=0.22{1}_{\ensuremath{-}0.044}^{+0.056}$, close to the recent analysis with updated datasets and PHENIX measurements and the lattice QCD simulations. We subsequently present the unpolarized and polarized gluon generalized parton distributions in the proton.