Related papers: Photon Structure
We discuss a possible measurement of the ratio of the nucleon structure functions, F2n/F2p, and the ratio of the up to down quark distributions, u/d, at large x, by performing deep inelastic electron scattering from the 3H and 3He mirror…
Several topics from the wide field of QCD studies in Deep-inelastic $ep$ Scattering at HERA are addressed. They include QCD analyses of the inclusive cross section with the determination of $\alpha_s$ and the proton gluon density from the…
Until very recently, two-photon interaction processes have been considered only as arising from second- or higher-order effects in driven systems, and so limited to extremely small coupling strengths. However, a variety of novel physical…
In the last decades, the blossoming of experimental breakthroughs in the domain of electron energy loss spectroscopy (EELS) has triggered a variety of theoretical developments. Those have to deal with completely different situations, from…
We show how the parton distributions in the photon can be accurately measured in the photoproduction of large-pt jets at HERA. A short review is given of the beyond Leading Logarithm formalism for the photon structure function, with a…
The proton structure function is re-deduced from the data of deep inelastic electron-proton scattering after enhanced correction that is made due to the multiple scattering effect. The Glauber approach is used to account for the multiple…
The description of the structure of proton is fundamental in order to describe the standard model processes at the LHC as well as for the searching of New Physics. Quantum fluctuations imply the presence of photons and leptons inside the…
The first measurements of the longitudinal proton structure function FL in deep inelastic positron-proton scattering at low Bjorken x are described. Theoretical predictions in higher order QCD and using dipol model calculations are…
The $O(\alpha^2\log(Q^2/m_e^2))$ leptonic QED corrections to unpolarized deeply inelastic electron-nucleon scattering are calculated in the mixed variables.
Photoproduction of jets at HERA provides information on the partonic structure of the photon. We report on the latest dijet photoproduction results, for real photons and for photons at low virtualities, measured with the ZEUS detector.
Lepto-nuclear colliders offer unique experimental opportunities to probe QCD in an extended medium. Of the many possibilities, three experiments are described here that are clearly feasible and of high scientific importance. First, a direct…
Several preliminary QCD results from e+e- interactions at LEP are reported. These include studies of event shape variables, which are used to determine alpha_s and for studies of the validity of power corrections. Further, a study of color…
We investigate the QED Compton process (both elastic and inelastic) in unpolarized and longitudinally polarized electron-proton scattering. The cross section can be expressed in terms of the equivalent photon distribution of the proton. We…
In this talk I first briefly explain the puzzle presented by the high muon content observed in air-showers which point to the ultra high-energy $\gamma$ sources like the HER-X-1. Since it had been suggested that a possible explanation of…
One of the most intriguing problems of light transport in solids is the localization that has been observed in various disordered photonic structures1-11. The light localization in defect-free icosahedral quasicrystals has recently been…
Parameter-free and perturbatively stable leading order (LO) and next-to-leading order (NLO) parton densities for real and virtual photons are presented.
Precise proton and neutron form factor measurements at Jefferson Lab, using spin observables, have recently made a significant contribution to the unraveling of the internal structure of the nucleon. Accurate experimental measurements of…
We argue that recent results from two-photon processes at LEP are better explained by quarks possessing integer electric charges.
Recent results on measurements of the strong coupling $\alpha_S$ from LEP are reported. These include analyses of the 4-jet rate using the Durham or Cambridge algorithm, of hadronic $Z^0$ decays with hard final state photon radiation, of…
Various QCD studies based on jet observables in hadronic final states in deep-inelastic scattering and hadron-hadron collisions are presented. Measured quantities are event shape variables, jet rates and jet cross sections. QCD analyses…