Related papers: Threshold-improved predictions for charm productio…
We investigate the twist four longitudinal structure function $F_{L}^{\tau=4}$ of deep inelastic scattering and show that the integral of ${F_{L}^{\tau=4} \over x}$ is related to the expectation value of the fermionic part of the…
We review recent developments in the calculation of deep-inelastic structure functions to next-to-next-to leading order in perturbative QCD. We discuss the impact of these corrections on the determination of the strong coupling alpha_s and…
We present measurements on D*+- production cross sections in deep inelastic e+p scattering with 1<Q^2<600 GeV^2 and 0.02<y<0.7 in two restricted kinematic regions in p_t(D*) and eta(D*). The decay channels D*+ -> D0 pi+ with subsequent…
We present a first calculation of the heavy flavor contribution to the longitudinally polarized deep-inelastic scattering structure function $g_1^{Q}$, differential in the transverse momentum or the rapidity of the observed heavy quark $Q$…
We analyze power corrections to flavour singlet deep inelastic scattering structure functions in the framework of the infrared renormalon model. Our calculations, together with previous results for the non-singlet contribution, allow to…
In the collinear twist-three approach, we calculate for the first time the gluon contribution to double (longitudinal-transverse) spin asymmetry A_{LT} for open charm production in proton-proton collisions measurable at RHIC. Utilizing the…
We present measurements of charm production in DIS using the ZEUS detector. Data with an integrated luminosity of 83 pb$^{-1}$ have been analysed. For the channel $D^{*+} \to D^{0}\pi_{s}^{+} \to K^{-}\pi^{+}\pi_{s}^{+} (+ c.c.)$ a cross…
The effect of gluon shadowing on charm quark production in large impact parameter ultrarelativistic heavy ion collisions is investigated. Charm production cross sections are calculated for a range of non-central impact parameters which can…
We perform an extensive study of the scale dependence of flavor-singlet contributions to the structure function g_2(x,Q^2) in polarized deep-inelastic scattering. We find that the mixing between quark-antiquark-gluon and three-gluon twist-3…
Recent results on the production of open charm in electron proton scattering at HERA are reviewed. Results on the fragmentation of charm are presented and compared to the measurements at e+e- colliders. Recent results on the charm…
The pomeron structure function is extracted from the latest H1 data and are subject to a QCD analysis. The result shows evidence for gluon recombination.
In charged current deep inelastic scattering charm is dominantly produced in scattering events on strange quarks, thereby allowing for an experimental determination of the nucleon's strange sea density. A measurement of the energy spectrum…
We perform an analysis of the relation between the factorization scale and the masses of the quarks in the calculation of the hard gluon coefficient in polarized deep inelastic scattering. Particular attention is paid to the role of strange…
We perform a next-to-leading-order QCD analysis to world data on polarized structure functions $g_1$ and $g_2$ in a fixed-flavor number scheme. We include target mass corrections and higher twist effects in our fitting procedure and study…
We investigate the effect of the structure function F_L in global parton analyses of deep inelastic and related hard scattering data. We perform NLO and NNLO analyses which include the reduced cross section HERA data at high y, as well as…
We report on a recent extraction of the higher twist contributions to the deep inelastic structure functions $F_2^{ep,ed}(x,Q^2)$ in the large $x$ region. It is shown that the size of the extracted higher twist contributions is strongly…
Within the framework of a high-twist approach, we calculate the next-to-leading order (NLO) perturbative QCD corrections to the transverse momentum broadening in semi-inclusive hadron production in deeply inelastic $e+A$ collisions, as well…
A next-to-leading order Monte Carlo program for the calculation of heavy quark cross sections in deeply inelastic scattering is described. Concentrating on charm quark and D^*(2010) production at HERA, several distributions are presented…
Charmed meson production in semi-inclusive deep inelastic scattering is investigated in the color dipole formalism. The transverse momentum distributions are calculated. We find good agreement with the H1 data using a hard fragmentation…
The twist 2 and twist 3 contributions of the polarized deep-inelastic structure functions are calculated both for neutral and charged current interactions using the operator product expansion in lowest order in QCD. The relations between…