Measurement of the Open-charm Contribution to the Diffractive Proton Structure Function

Production of D*±(2010) mesons in diffractive deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb-1. Diffractive events were identified by the presence of a large rapidity gap in the final state. Differential cross sections have been measured in the kinematic region 1.5<Q2<200 GeV2, 0.02<y<0.7, xP<0.035, β<0.8, pT(D*±)>1.5 GeV and η(D*±) <1.5. The measured cross sections are compared to theoretical predictions. The results are presented in terms of the open-charm contribution to the diffractive proton structure function. The data demonstrate a strong sensitivity to the diffractive parton densities.