Charm production at HERA

TL;DR

This paper analyzes charm production at HERA, showing that the charm structure function fits a hard pomeron model and that combining it with a soft pomeron explains elastic J/psi photoproduction.

Contribution

It demonstrates that charm production data at HERA can be described by a flavor-blind hard pomeron, extending understanding of diffraction and vector meson production.

Findings

Charm structure function F_2^c fits a single power of x.

Hard pomeron exchange describes charm data well.

Combining hard and soft pomerons explains J/psi photoproduction.

Abstract

The ZEUS data on the charm structure function F_2^c at small x fit well to a single power of x, corresponding to the exchange of a hard pomeron that is flavour-blind. When combined with the contribution from the exchange of a soft pomeron, the hard pomeron gives a good description of elastic $J/\psi$ photoproduction.