Measurement of D mesons production in deep inelastic scattering at HERA

The Hadron Electron Ring Accelerator, HERA, is a unique facility to study the scattering between electrons and protons at very high energies. The two colliding experiments at HERA, ZEUS and H1, have been giving important contributions to the understanding of the subatomic world. In this talk, the analysis of charm production in deep inelastic scattering measured with the ZEUS detector at HERA will be presented. Charm has been tagged by reconstructing $D^{*+}$, $D^0$, $D^+$ and $D_s^+$ charm mesons in the kinematic range$p_T(D^{*+},D^0,D^+) > 3$ GeV, $p_T(D_s^+) > 2$ GeV and $|\eta(D)|< 1.6$ for $1.5 < Q^2 < 1000$ GeV$^2$ and $0.02 < y < 0.7$. The production cross sections were used to extract the charm fragmentation ratios and the fraction of $c$ quarks hadronising into a charm meson. The cross sections were compared to the next-to-leading-order QCD predictions, and extrapolated to the full kinematic region in $p_T(D)$ and $\eta(D)$ in order to determine the open-charm contribution, $F_2^{c\bar c}(x,Q^2)$, to the proton structure function $F_2$.