2022

Lappi, Tuomas; Mäntysaari, Heikki; Penttala, Jani

We present results for higher-order corrections to exclusive J/ψJ/ψ production. This includes the first relativistic correction of order v2v2 in quark velocity, and next-to-leading order corrections in αsαs for longitudinally polarized production. The relativistic corrections are found to be important for a good description of the HERA data, especially at small values of the photon virtuality. The next-to-leading order results for longitudinal production are evaluated numerically. We also demonstrate how the vector meson production provides complementary information to the structure functions for extracting the initial condition for the small-xx evolution of the dipole-proton scattering amplitude.