Related papers: Hard Processes in Electron-Proton Scattering
New results on charm and beauty electroproduction from the H1 and ZEUS Collaborations at the ep collider HERA are presented. Differential cross sections are compared to a next-to-leading order QCD calculation. The heavy quark contributions,…
A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised ep scattering at HERA during the period 1994-2000. The data span six orders of…
We discuss the theoretical approach and practical algorithms for simulation of radiative events in elastic ep-scattering. A new Monte Carlo generator for real photon emission events in the process of elastic electron-proton scattering is…
A model-independent search for deviations from the Standard Model prediction is performed in e-p collisions at HERA II using H1 data recorded during the years 2005 and 2006, corresponding to an integrated luminosity of 159 inv.pb. All event…
A measurement of the inclusive deep-inelastic neutral current e+p scattering cross section is reported in the region of four-momentum transfer squared, 12<=Q^2<=150 GeV^2, and Bjorken x, 2x10^-4<=x<=0.1. The results are based on data…
The elastic hadron-hadron scattering at high energies is one of the most fundamental subjects of all particle physics problems and yet is least understood in spite of many advances in quantum chromodynamics (QCD) at the conceptual level. We…
This article describes different approaches to investigate the behavior of parton evolution in the proton by exploiting various aspects of the hadronic final state produced in Deep Inelastic Scattering Events at HERA.
We pursue the hypothesis that the events with a large rapidity gap, observed at HERA, reflect the scattering of electrons off lumps of wee partons inside the proton. A simple scaling behaviour is predicted for the diffractive structure…
Real Compton Scattering on the proton in the hard scattering regime is investigated. Recent theoretical developments are reviewed. Plans for new experimental studies at Jefferson Laboratory are presented.
Using the H1 detector at HERA, charged particle multiplicity distributions in deep inelastic ep scattering have been measured over a large kinematical region. The evolution with $W$ and $Q^2$ of the multiplicity distribution and of the…
We investigate the reaction $e p \to e PS X$ where PS denotes a pseudoscalar meson $\pi^0, \eta, \eta'$, or $\eta_c$ and X either a proton or resonance or continuum states into which the proton can go by diffractive excitation. At high…
The electromagnetic processes of Compton scattering and photon splitting/merging are investigated in the presence of strongly magnetized electron-positron plasma. The influence of these processes on the radiation transfer in the…
A brief review is given of the status of nucleon spin structure functions as determined from polarized deep inelastic lepton-nucleon scatttering, including current outstanding problems. The characteristics of a polarized HERA collider, some…
HERA is the only high energy electron-proton collider in the world today and hence has unique opportunities both to probe the structure of the proton and to search for physics beyond the Standard Model. Results are presented for…
The dependence of the fractal behaviors of the pomeron induced system in deep inelastic lepton-nucleon scattering upon the diffractive kinematic variables is found rather robust and not sensitive to the distinct parameterization of the…
We consider exclusive $\pi^0$ production in ep-scattering. At high energies odderon and photon exchange contribute. The photon exchange contribution is evaluated exactly using data for the total virtual photon-proton absorption cross…
The physics case for a possible fixed target polarized nucleon-nucleon collision experiment at HERA is described. The experiment named HERA-N could be realized using an internal polarized gas target in the HERA polarized/unpolarized proton…
The H1 and ZEUS experiments at the HERA $e^\pm p$ collider at Hamburg have recently reported some anomalous hard-scattering events, which could be indicative of new physics beyond the standard model. I have tried to discuss in a…
Diffractive reactions involving a hard scale can be understood in terms of quarks and gluons. These reactions have become a valuable tool for investigating the low-x structure of the proton and the behavior of QCD in the high-density…
In the last couple of years, the LHC has released precise measurements of elastic proton-proton scattering which has become an important guide in the search for selecting phenomenological models and theoretical approaches to understand, in…