Gravitational form factors of the proton from near-threshold vector meson photoproduction

Abstract

We embark on a systematical analysis of the quark and gluon gravitational form factors (GFFs) of the proton, by connecting energy-momentum tensor and the near-threshold vector meson photoproduction (NTVMP). Concretely, the quark contributions of GFFs are determined unprecedentedly by global fitting the cross section of the lightest vector meson ρ0 photoproduction. Combined with the gluon GFFs achieved from heavy quarkonium J/ψ photoproduction data, the complete GFFs are obtained and compared with the deeply virtual Compton scattering experimental results and LQCD determinations. The profound implications of this finding cannot be overstated, as it opens new avenues for obtaining comprehensive information on GFFs. Naturally, this work is not only an important basis for delving the proton enigmatic properties, but also have significance theoretical guiding for future JLab and EICs experimental measurements.