相关论文: Photoproduction models for total cross section and…
We demonstrate how to efficiently expand cross sections for color-singlet production at hadron colliders around the kinematic limit of all final state radiation being collinear to one of the incoming hadrons. This expansion is…
We have calculated inclusive two-jet cross sections in next-to-leading order QCD for direct photoproduction in low $Q^2$ $ep$ collisions at HERA. Infrared and collinear singularities in real and virtual contributions are cancelled with the…
Differential photoproduction cross sections are measured for events containing D* mesons. The data were taken with the H1 detector at the ep collider HERA and correspond to an integrated luminosity of 51.1 pb-1. The kinematic region covers…
I discuss the minijet contribution to total photoproduction and photon--photon cross sections. While minijets with $p_T$ around 2 GeV have recently been observed directly in \gamgam\ experiments, the total \gamp\ cross section measured at…
The relation of model predictions for muon content of extensive air showers (EAS) to particular properties of hadron-air interactions is discussed. Further, using a new Monte Carlo generator of cosmic ray interactions, QGSb, the relevance…
The hadronization procedure of the QGSJET-III Monte Carlo (MC) generator of high energy hadronic interactions is discussed. Selected results of the model, regarding production spectra of secondary particles, are presented in comparison to…
A study of $3+1$ jet event photoproduction at HERA is presented. We define an angular variable which is sensitive to the topology of the final state jets and is therefore able to discriminate between the different contributing subprocesses,…
In this work, the relation between muon production in extensive air showers and features of hadronic multiparticle production at low energies is studied. Using CORSIKA, we determine typical energies and phase space regions of secondary…
We present a Monte-Carlo approach to prompt-photon production, where photons and QCD partons are treated democratically. The photon fragmentation function is modelled by an interleaved QCD+QED parton shower. This known technique is improved…
Dijet cross sections are presented using photoproduction data obtained with the ZEUS detector during 1994. These measurements represent an extension of previous results, as the higher statistics allow cross sections to be measured at higher…
We develop a potential algorithm to relate the depth development of ultra high energy extensive air showers and the time delay for individual muons. The time distributions sampled at different positions at ground level by a large air shower…
We discuss the first applications of our newly developed Monte Carlo event generator SOPHIA to multiparticle photoproduction of relativistic protons with thermal and power law radiation fields. The measured total cross section is reproduced…
Rho photoproduction on complex nuclei is re-examined using a generalised vector dominance model which succesfully predicts the observed nuclear shadowing in real photoabsorption and deep inelastic scattering. This model is shown to give a…
The model dependence of the development of extensive air showers generated by high-energy cosmic-ray particles in the atmosphere is studied. The increase of proton-proton and proton-air inelastic cross-sections and values for the elasticity…
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 cross section for photoproduction of an isolated prompt photon in association with a jet is studied in Next-to-Leading Order. The kinematics are those appropriate for the DESY $ep$ collider HERA. The effects on the cross section of…
The cross section for the photoproduction of events containing three jets with a three-jet invariant mass of M_3J > 50 GeV has been measured with the ZEUS detector at HERA. The three-jet angular distributions are inconsistent with a uniform…
We demonstrate that jet observables are highly sensitive to the characteristics of the vacuum and the in-medium QCD parton showers and propose techniques that exploit this sensitivity to constrain the mechanism of quark and gluon energy…
The problem of extracting photoproduction amplitudes uniquely from so called complete experiments is discussed. This problem can be considered either for the extraction of full production amplitudes, or for the determination of multipoles.…
The new hadronic Monte Carlo model QGSJET-II is applied for extensive air shower (EAS) calculations. The obtained results are compared to the predictions of the original QGSJET and of the SIBYLL 2.1 interaction models. It is shown that…