Measurement of Inclusive and Dijet D* Meson Cross Sections in   Photoproduction at HERA
  The inclusive photoproduction of D\ast mesons and of D\ast-tagged dijets is investigated with the H1 detector at the ep collider HERA. The kinematic region covers small photon virtualities Q2 < 2 GeV2 and photon-proton centre-of-mass energies of 100 < Wgp < 285 GeV. Inclusive D\ast meson differential cross sections are measured for central rapidities |eta(D\ast)| < 1.5 and transverse momenta pT (D\ast) > 1.8 GeV. The heavy quark production process is further investigated in events with at least two jets with transverse momentum pT (jet) > 3.5 GeV each, one containing the D\ast meson. Differential cross sections for D\ast-tagged dijet production and for correlations between the jets are measured in the range |eta(D\ast)| < 1.5 and pT (D\ast) > 2.1 GeV. The results are compared with predictions from Monte Carlo simulations and next-to-leading order perturbative QCD calculations. 
H1 Collaboration
hep-ex