Speaker
Description
High-statistics total cross sections for the vector meson photoproduction at the threshold: g𝑝 -> omega 𝑝 (from A2 at MAMI, ELPH, and CBELSA/TAPS), gp -> rho p (from CLAS12), gamma 𝑝 -> phi 𝑝 (from CLAS6 and LEPS), and gamma 𝑝 -> 𝐽/psi 𝑝 (from GlueX, 007, and CLAS12) allow one to extract the absolute value of vector meson nucleon scattering length using VMD model. The “young” vector meson hypothesis may explain why the obtained scattering length for the nucleon-phi meson, compared to the typical hadron size of approximately 1 fm, indicates that the proton is more transparent to the phi meson than to the omega meson and is much less transparent to the 𝐽/psi meson. The extended analysis of upsilon-meson photoproduction using quasi-data from the QCD approach is in perfect agreement with the light-meson findings using experimental data. An estimation of the J/psi p scattering length on the bound proton for the light nuclei (from SRC/CT quasi-data) was obtained.