Related papers: A photon-proton marriage
The photoproduction of isolated photons has been measured in diffractive events recorded by the ZEUS detector at HERA. Cross sections are evaluated in the photon-proton transverse-energy and pseudorapidity ranges 5<ET(gamma)<15 GeV and…
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…
Cross sections for elastic and proton-dissociative photoproduction of J/psi mesons are measured with the H1 detector in positron-proton collisions at HERA. The data were collected at $ep$ centre-of-mass energies sqrt{s} approx 318 GeV and…
This is a short review of the properties of electron proton interactions characterized by the presence of large rapidity gaps (LRG) in the measured hadronic final state as obtained by the ZEUS Collaboration at the HERA Collider. In the deep…
First inclusive measurements of isolated prompt photons in photoproduction at the HERA ep collider have been made with the ZEUS detector, using an integrated luminosity of 38.4 pb$^{-1}$. Cross sections are given as a function of the…
It is shown that the hadronic dissociation of space-like $(Q^2>0)$ photons can be directly probed by performing measurements in the fragmentation region of transversely polarized and unpolarized proton beams at the electron-proton collider…
Experimental data on the shape of hadronic momentum spectra are compared to theoretical predictions in the context of calculations in the Modified Leading Log Approximation (MLLA), under the assumption of Local Parton Hadron Duality (LPHD).…
The high rates of multi-parton interactions at the LHC can provide a unique opportunity to study the multi-parton structure of the hadron. To this purpose high energy collisions of protons with nuclei are particularly suitable. The rates of…
New results reported at the Moriond-QCD 2003 conference from the experiments ALEPH, DELPHI, L3, and OPAL on the structure of the photon as well as heavy quark production in gammagamma collisions are presented. The hadronic structure of the…
We apply the target rest frame formalism to photon + heavy quark production cross section in hadronic collisions at high energies. We investigate the dependence of the production cross section on the photon and quark rapidities and…
Physics from the polarized electron or positron beam colliding with the unpolarized proton beam at HERA-II as well as from the unpolarized ep collisions at HERA-I is discussed. Results shown include (i) inclusive neutral and charged current…
The hadronic interactions of the photon are studied in terms of new measurements of the total hadronic cross section and di-jet production in photon-photon collisions at LEP2.
The diffractive photoproduction of J/psi mesons is measured with the H1 detector at the ep collider HERA using an integrated luminosity of 78 pb^-1. The differential cross section d sigma(gamma p -> J/psi Y) / d t is studied in the range 2…
Transverse momentum spectra of charged particle production in heavy-ion collisions are considered in terms of a recently introduced Two Component parameterization combining exponential ("soft") and power-law ("hard") functional forms. The…
A measurement of the beauty production cross section in ep collisions at a centre-of-mass energy of 319 GeV is presented. The data were collected with the H1 detector at the HERA collider in the years 1999-2000. Events are selected by…
The ZEUS detector has been used to study dissociation of virtual photons in events with a leading proton, gamma^* p -> X p, in e^+p collisions at HERA. The data cover photon virtualities in two ranges, 0.03<Q^2<0.60 GeV^2 and 2<Q^2<100…
In this letter we study the photoproduction of heavy quarks and vector mesons in the coherent proton-nucleus (pA) interactions for RHIC and LHC energies and analyze if these processes can be used to determine the QCD dynamics at high…
The cross section of the $D^*$-meson diffractive photoproduction at the HERA collider has been calculated in the framework of perturbatively motivated model for the different kinematic regions. The camparison between the different Pomeron…
Prompt photons, together with an accompanying jet, have been studied in the photoproduction regime of ep scattering with the ZEUS detector at HERA. Predictions based on leading-logarithm parton-shower Monte Carlo models and…
A detailed study of vector meson production ($\phi$ and $J/\psi$) in $e^\pm p$ collisions at HERA with the ZEUS and H1 detector has been performed. The cross sections are measured as a function of $Q^2$, $W$ and $t$. In this contribution,…