Diffractive Open Charm Production in Deep-Inelastic Scattering and Photoproduction at HERA

TL;DR

This paper reports measurements of diffractive open charm production at HERA, using two analysis techniques, and finds good agreement with QCD predictions, supporting the validity of QCD factorization in these processes.

Contribution

It presents the first detailed measurements of diffractive open charm production in both DIS and photoproduction at HERA, validating QCD factorization assumptions.

Findings

Good agreement with next-to-leading order QCD predictions

Supports QCD factorization in diffractive open charm production

Uses two complementary analysis techniques

Abstract

Measurements are presented of diffractive open charm production at HERA. The event topology is given by ep -> eX Y where the system X contains at least one charmed hadron and is well separated by a large rapidity gap from a leading low-mass proton remnant system Y. Two analysis techniques are used for the cross section measurements. In the first, the charm quark is tagged by the reconstruction of a D*(2010) meson. This technique is used in deep-inelastic scattering (DIS) and photoproduction. In the second, a method based on the displacement of tracks from the primary vertex is used to measure the open charm contribution to the inclusive diffractive cross section in DIS. The measurements are compared with next-to-leading order QCD predictions based on diffractive parton density functions previously obtained from a QCD analysis of the inclusive diffractive cross section at H1. A good agreement is observed in the full kinematic regime, which supports the validity of QCD factorization for open charm production in diffractive DIS and photoproduction.