相关论文: Diffractive charm photoproduction at HERA ep-colli…
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…
The first measurement of D*+/- meson diffractive photoproduction cross sections has been performed with the ZEUS detector at the HERA $ep$ collider, using an integrated luminosity of 38 pb^-1. The measurement has been performed for…
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…
The two gluon exchange model of the pomeron is used to compute the photoproduction reaction $\gamma p \to Z^0 p$. The predicted cross section is too small to be observed at HERA, but may be detectable at an eventual Next Linear Collider.
The cross section for the diffractive reaction gamma* + p -> c cbar + p with a real or virtual photon is calculated in the nonperturbative two-gluon exchange model of Landshoff and Nachtmann. Numerical predictions are given for cross…
We demonstrate that perturbative QCD allows one to calculate the absolute cross section of diffractive exclusive production of photons at large $Q^2$ at HERA, while the aligned jet model allows one to estimate the cross section for…
Elastic and proton-dissociative photoproduction of $\rho^0$, $\phi$ and $J/\psi$ vector mesons ($\gamma p\to Vp$, $\gamma p\to VN$, respectively) have been measured in e^+p interactions at HERA up to -t=3 GeV$^2$, where t is the…
The proton-dissociative diffractive photoproduction of J/psi mesons has been studied in ep collisions with the ZEUS detector at HERA using an integrated luminosity of 112 pb^-1. The cross section is presented as a function of the…
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…
The measured D*+/-, D0, D+/-, D_s+/- and /\_c+/- photoproduction cross sections have been used to determine charm fragmentation ratios and fractions of c quarks hadronising as a particular charm hadron, f(c -> D, /\_c). Events with a D*+/-…
Results from a phenomenological analysis for diffractive hadroproduction of heavy flavors at high energies are reported. Diffractive production of charm, bottom and top are calculated using Regge factorization, taking into account recent…
A measurement of the inclusive cross-section for the photoproduction of protons in the central fragmentation region at HERA is presented. The measured cross-section is compared with the prediction of the PYTHIA MC model. The obtained value…
The exclusive diffractive production of vector mesons and real photons in ep collisions has been studied at HERA in a wide kinematic range. Here the most recent experimental results are presented together with a Regge-type model and…
A measurement is presented of dijet and 3-jet cross sections in low-|t| diffractive deep-inelastic scattering interactions of the type ep -> eXY, where the system X is separated by a large rapidity gap from a low-mass baryonic system Y.…
Selected recent results from the H1 and ZEUS experiments are reviewed, illustrating some of the many facets of ``meson physics'' at the HERA ep collider. The results cover exclusive elastic and proton-dissociative diffractive vector meson…
We use perturbative QCD and parton-hadron duality to estimate the cross sections for the diffractive electroproduction of rhoprime(1-) and rho(3-) resonances which occur in the 1.3-1.8 GeV mass interval. We present the cross sections and…
Recent results of open charm and beauty production in electron proton scattering at HERA are presented. In photoproduction, the measured cross sections for charm exceed fixed order NLO QCD calculations. Experimental evidence supports the…
Recent experimental data on dijet cross sections in diffractive photoproduction at HERA collider are analysed with an emphasis on QCD factorisation breaking effects. The possible sources of the contradiction in conclusions of H1 and ZEUS…
The next--to--leading order inclusive cross section for large-$p_\perp$ photoproduction of charm quarks at HERA is calculated in two different approaches. In the first approach the charm quarks are treated as massive objects which are…
The production of D^0, D^*+, D^+, D_s+ and Lambda_c^+ charm hadrons and their antiparticles in ep scattering at HERA has been studied with the ZEUS detector, using a total integrated luminosity of 372 pb^-1. The fractions of charm quarks…