Related papers: The charm contribution into the proton structure f…
We report on a measurement of the proton structure function $F_2$ in the range $3.5\times10^{-5}\leq x \leq 4\times10^{-3}$ and 1.5 ${\rm GeV^2} \leq Q^2 \leq15$ ${\rm GeV^2}$ at the $ep$ collider HERA operating at a centre-of-mass energy…
The charm quark structure function $F^c_2$ and the longitudinal structure function $F_l^p$ are directly sensitive to the gluon content of proton and therefore are crucial in understanding of proton structure function, in particular at low…
We estimate the differential and total cross sections for both the photoproduction of vector D*-meson and its yield in deep inelastic scattering at the HERA collider in the framework of model motivated by perturbative calculations in QCD.…
Selected recent ZEUS and H1 results on open charm and beauty production in high energy ep collisions are reviewed. Measurements of differential D* cross sections, charm meson production ratios and semi-leptonic beauty decays are discussed…
A resently developed generalization of the Quark--Gluon String Model to the case of bosonic resonances production in hadron--hadron collisions is used for the calculation of inclusive production of charmed mesons $D$, $D^*(2010)$ and…
The production of beauty and charm quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared 5 < Q^2 < 1000 GeV^2 using an integrated luminosity of 354 pb^{-1}. The beauty and charm…
Data for D*(2010) meson electroproduction in the range 10 < Q2 < 1350 GeV^2 has recently been presented by the ZEUS collaboration at HERA. We use these results together with previously published data for Q2 > 1 GeV^2 to test whether one can…
Jet and charm quark production in diffractive interactions is sensitive to the partonic structure of the diffractive exchange. This article reviews recent cross section measurements of such processes in both deep-inelastic scattering (DIS)…
The production of the excited charm mesons D_1(2420) and D^*_2(2460) in ep collisions has been measured with the ZEUS detector at HERA using an integrated luminosity of 373 pb^{-1}. The masses of the neutral and charged states, the widths…
Measurements are presented of inclusive charm and beauty cross sections in e^+p collisions at HERA for values of photon virtuality Q^2 > 150 GeV^2 and of inelasticity 0.1 < y < 0.7. The charm and beauty fractions are determined using a…
We study the expansion method for the gluon distribution function at low x values and calculate the charm structure functions in the LO and NLO analysis. Our results provide a compact formula for the ratio $R^{c} =F^{c}_{L}/F^{c}_{2}$,…
An overview over the recent heavy flavour results of the H1 and ZEUS collaborations is presented. Various techniques to tag the heavy quark, which allow to explore different phase space regions, are employed. Predictions of pertubative QCD…
Recent measurements of beauty production in ep collisions at HERA are presented. The results were obtained using data from the experiments H1 and ZEUS from the years 1996 to 2000 (HERA I). An outlook is given for analysis on data from HERA…
At the electron-proton collider HERA the inclusive $D^{*\pm}$ meson photoproduction cross section has been measured with the H1 detector in two different, but partly overlapping, kinematical regions. For the first, where $<W_{\gamma p}>…
We calculated the contribution of the photon hadronic component in the charmed structure function of the leptoproduction. The contribution comes from scattering of the c quarks of the virtual photon on the quarks and gluons of the proton.…
Measurements of $D^{*}(2010)$ meson production in diffractive deep inelastic scattering $(5<Q^{2}<100~{\rm GeV}^{2})$ are presented which are based on HERA data recorded at a centre-of-mass energy $\sqrt{s} = 319{\rm~GeV}$ with an…
In the leading order of perturbative QCD one calculates the total and differential cross-sections for the hadronic production of doubly charmed baryons $\Xi_{cc}$ and $\Xi_{cc}^*$ in different experiments. The experimental evaluation of…
Inclusive charm meson production cross sections in the deep inelastic scattering and photoproduction regimes are compared with QCD leading and next-to-leading (NLO) calculations. The NLO predictions are significantly below the data in some…
We show that the cross section for inclusive charm production exhibits geometric scaling in a large range of photon virtualities. In the HERA kinematic domain the saturation momentum $Q_{sat}^2(x)$ stays below the hard scale…
The charm fragmentation function has been measured in D* photoproduction with the ZEUS detector at HERA using an integrated luminosity of 120 pb-1. The fragmentation function is measured versus z = (E+p_parallel){D*}/2E{jet}, where E is the…