We analyze the exclusive ϕ-meson photoproduction on both hydrogen and deuterium targets based on the published data of CLAS, SAPHIR and LEPS collaborations. A dipole-form scalar gravitational form factor is applied to describe the ∣t∣-dependence of the differential cross section. Based on the average of all the near-threshold data from CLAS, SAPHIR and LEPS, we find that the proton and deuteron mass radii are 0.75±0.02 fm and 1.95±0.19 fm respectively. The coherent and near-threshold quarkonium photoproduction seems to be sensitive to the radius of the hadronic system. The vector-meson-dominance model together with a low-energy QCD theorem well describe the data of near-threshold ϕ photoproduction on the hadronic systems.
@article{arxiv.2108.03550,
title = {Proton and deuteron mass radii from near-threshold $\phi$-meson photoproduction},
author = {Rong Wang and Wei Kou and Chengdong Han and Jarah Evslin and Xurong Chen},
journal= {arXiv preprint arXiv:2108.03550},
year = {2021}
}