Related papers: Photoproduction at low Q^2
We discuss the inclusive jet production at HERA in the next-to-leading logarithm approximation. Theoretical uncertainties are considered in some details. We show the importance of the jet rapidity distribution to constrain the parton…
A study of the $\J$-meson photoproduction at large transverse momentum at HERA energies via the charm quark excitation in the photon is presented. Based on perturbative QCD, nonrelativistic quark model and photon structure function…
I review recent progress on the Higgs production in gamma gamma collisions at the photon mode of the Next Linear Collider (NLC). I mainly focus on two particular topics. The first topic is the Higgs-two photon vertex, which is sensitive to…
The planed HERA upgrade will increase the integrated luminosity by two orders of magnitude.A new program of electron-nucleus collisions at HERA is under discussion now.In this connection we present prospects for the study of a light neutral…
We present next-to-leading order calculations of one- and two-jet production in eP collisions at HERA for photon virtualities in the range 1<Q^2<100 GeV^2. Soft and collinear singularities are extracted using the phase space slicing method.…
We study various conceivable photoproduction reactions in a polarized ep collider mode of HERA with respect to their sensitivity to the proton's polarized gluon distribution. A special emphasis is put on the `resolved' part of the cross…
We show that the recent measurements of the total photoproduction cross section at HERA energies [1] are in agreement with our earlier prediction based on high-energy hadronic structure of the photon in the QCD minijet-type model [2]. We…
The theoretical description of heavy quarkonium production at high-energy p-pbar and e-p colliders is reviewed. Predictions based on non-relativistic QCD factorisation are confronted with recent charmonium and bottomonium data from the…
The photoproduction of Drell-Yan lepton pairs at HERA is studied. We show that in the backward rapidity region the cross section is strongly sensitive to the small-$x$ behaviour of the quark distributions in the proton, and that with…
Processes of hevy quark photoproduction at HERA energies and beyond are investigated using the semihard ($k_{\bot}$ factorization) approach. The virtuality and longitudinal polarization of gluons in the photon - gluon subprocess as well as…
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}>…
The import of HERA data on heavy quark production for LHC experiments is discussed. Knowlegde of all aspects of the beauty and charm production process, viz. the parton density functions of colliding hadrons, the hard scatter, and the…
We quantify perturbative and non-perturbative QCD effects in the exclusive $J/\psi$-photoproduction cross section, and in the shrinkage of the differential cross section with respect to momentum transfer, $t$. We predict that in the high…
The high energy photoproduction of jets is being observed at the ep collider, HERA. It may be that the HERA centre-of-mass energy is sufficiently large that the production of more than one pair of jets per ep collision becomes possible,…
The excess of high-Q2 events recently observed in deep-inelastic positron-proton scattering at HERA has refuelled speculations on physics beyond the standard model, in particular on low-mass leptoquark-type particles. We review the…
Results of our next-to-leading order analytic calculation for longitudinally polarized photoproduction of heavy quarks are presented. Certain differential cross sections and the corresponding asymmetries are computed for energy ranges…
In this work we analyse the possibility of constraining the QCD dynamics at high energies studying the heavy quark photoproduction at LHC in coherent interactions. The rapidity distribution and total cross section for charm and bottom…
Diffractive processes in photon-proton interactions at HERA offer the opportunity to improve the understanding of the transition between the soft, non-perturbative regime in hadronic interactions at $Q^2 = 0$ and the perturbative region at…
Protons and antiprotons at collider energies are a source of high energy Weizsaecker--Williams photons. This opens up a possibility to study at the LHC exclusive photoproduction of heavy vector mesons at energies much larger than possible…
We review measurements of open beauty production at HERA, with emphasis on recent results based on lifetime signatures. The beauty cross sections in photoproduction and deep-inelastic scattering are found to be higher than expected in QCD…