Photoproduction and electroproduction of charm at high energies

TL;DR

This paper presents a QCD-motivated model to estimate charm meson production cross sections in high-energy photoproduction and deep inelastic scattering, aligning well with experimental data.

Contribution

It introduces a model that incorporates higher twists and color-octet hadronization effects, improving predictions for charm meson production at HERA.

Findings

Model accurately predicts cross sections for D*-meson production.

Inclusion of color-octet states improves data agreement.

Higher twist effects are significant at low transverse momentum.

Abstract

We estimate the differential and total cross sections for both the photoproduction of vector D*-meson and its yield in deep inelastic scattering at the HERA collider in the framework of model motivated by perturbative calculations in QCD. The offered model allows us to take into account higher twists over the transverse momentum of meson at p_T ~ m_c and to correctly approach the dominance of $c$-quark fragmentation at p_T >> m_c. We consider a possibility for the hadronization of color-octet c q-bar state into the meson. The combined contribution by the singlet and octet-color terms results in a good agreement with the experimental data for both the photoproduction and the production in deep inelastic scattering.