Gravitational form factors of the proton in the improved holographic QCD model

A bstract We compute the gluonic contribution to the gravitational form factors of the proton using the improved holographic QCD model, in which the proton is described in terms of bulk Dirac fermions. Model parameters are constrained using lattice and phenomenological input, allowing us to obtain estimates for the gravitational form factors and to compare them with results from other approaches. Using the extracted form factors, we analyze mechanical properties of the proton, including pressure and shear distributions. We obtain estimates for the mechanical and mass radii of the proton, ρ mech ≈ 0 . 63 fm, ρ mass ≈ 0 . 65 fm, and compare these values with radius estimates from other nonperturbative studies.