Related papers: QCD and total cross-sections: photons and hadrons
Photoproduction of a pair of particles with large invariant mass is a natural extension of collinear QCD factorization theorems which have been much studied for deeply virtual Compton scattering and deeply virtual meson production. We…
We calculate distributions of different vector mesons in purely exclusive ($p p \to p p V$) and semi-exclusive ($p p \to p X V$) processes with electromagnetic dissociation of a proton. The cross section for the electromagnetic dissociation…
The standard additive quark model and the ensuing counting rules are modified to take into account the quark-gluonic content of the Pomeron and of the secondary Reggeons. The result is that a much improved description of $pp, \pi p, \gamma…
In this note we address the issue of measurability of the hadronic cross-sections at a future photon collider as well as for the two-photon processes at a future high energy linear $e^+e^-$ collider. We extend, to higher energy, our…
Using J/psi and open charm photoproduction data, we apply the vector meson dominance model to obtain constraints on the energy dependence of the inelastic J/psi-nucleon cross section. Predictions of short distance QCD are in accord with…
Low Q2 photon-proton cross sections are analysed using a simple, QCD-motivated parametrisation $\sigma_{\gamma^\star p}\propto 1/(Q^2+Q_0^2)$, which gives a good description of the data. The Q2 dependence of the gamma* p cross section is…
The production of jets in low $Q^2$ $ep$ scattering (photoproduction) and in low $Q^2$ $e^+e^-$ scattering ($\gamma\gamma$ scattering) allows for testing perturbative QCD and for measuring the proton and photon structure functions. This…
We report on a successful attempt to extract the cross-section for the high-energy scattering of colour dipoles of fixed transverse size off protons using electroproduction and photoproduction total cross-section data, subject to the…
Accessing the forward kinematic regime of exclusive vector meson photoproduction is essential for probing the structure of the proton, yet this region is often experimentally inaccessible. We present a novel extrapolation of near-threshold…
We explore the possibility of using ultra-peripheral proton-lead collisions at the LHC to study inclusive vector-quarkonium photoproduction, that occurs when a quasi-real photon emitted by a fully stripped lead ion breaks a proton to…
We re\,examine the theory of hadronic photon-nucleon interactions at the quark-gluon level. The possibility of multiple parton collisions in a single photon-nucleon collision requires an eikonal treatment of the high-energy scattering…
We explain that the generalized vector meson dominance (GVMD) model is successful in describing hard high energy processes because it contains expected in QCD Color Coherent Phenomena. Within the model, which reproduces Bjorken scaling and…
Photoproduction is an important mode for the production of jets and electro-weak particles at lepton--lepton and lepton--hadron colliders and allows for interesting studies of exclusive production at hadron--hadron colliders. In this talk,…
The reactions gamma p -> K+ Lambda and gamma p -> K* Lambda are analyzed within perturbative QCD, allowing for diquarks as quasi-elementary constituents of baryons. The diquark-model parameters and the quark-diquark distribution amplitudes…
Cross sections for the reactions gamma^(*) gamma^(*) --> hadrons and gamma^(*) gamma^(*) --> 2 vector mesons are calculated as functions of energy (sqrt(s) > 20 GeV) and photon virtualities. Good agreement with experiment is obtained for…
We generalize our previous model for $\gamma^* p$ scattering to $\gamma \gamma$ scattering. Performing a new simultaneous fit to $\gamma^* p$ and $\gamma \gamma$ total cross section we find an optimal set of parameters to describe both…
Using the QCD color dipole picture to study exclusive vector meson and inclusive jet/open meson photoproduction, we calculate the ratio of elastic meson production to inclusive hadron production cross sections for ultraperipheral heavy ion…
We study inclusive photoproduction of hadrons at HERA via both direct and resolved photons to next-to-leading order (NLO) in the QCD-improved parton model. We predict transverse-momentum ($\pt$) and rapidity ($\ylab$) distributions and…
The rates of inclusive photo- and electroproduction of the eta_c meson: gamma* + p -> eta_c + X are calculated in the triple Regge region, integrated over the diffractive mass X. For the Regge exchanges we use the hard Pomeron and Odderon,…
Perturbative QCD is the appropriate tool to describe many important properties of the inclusive observables measured at electron-proton (or ion) colliders, such as the energy dependence of the total cross sections in well-chosen kinematical…