Higher-order corrections to exclusive heavy vector meson production

TL;DR

This paper calculates higher-order corrections to exclusive J/psi production, including relativistic and NLO QCD effects, improving agreement with experimental data and providing insights into small-x dipole-proton interactions.

Contribution

It introduces the first relativistic correction of order v^2 and NLO corrections in alpha_s for exclusive J/psi production, enhancing theoretical precision.

Findings

Relativistic corrections are crucial for matching HERA data at low photon virtuality.

NLO corrections in alpha_s are evaluated numerically for longitudinal production.

Vector meson production offers additional constraints on small-x dipole-proton scattering models.

Abstract

We present results for higher-order corrections to exclusive $\mathrm{J}/\psi$ production. This includes the first relativistic correction of order $v^2$ in quark velocity, and next-to-leading order corrections in $\alpha_s$ 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-$x$ evolution of the dipole-proton scattering amplitude.