Related papers: Photon Structure and gamma-gamma Physics
A summary is given of some recent QCD results from LEP. For LEP-2, the topics include event shape measurements, determinations of the strong coupling constant, and measurements of the charged particle multiplicity distribution at the…
In spatially structured strong laser fields, quantum electrodynamical vacuum behaves like a nonlinear Kerr medium with modulated third-order susceptibility where new coherent nonlinear effects arise due to modulation. We consider the…
We compute the structure function, transverse momentum dependent parton distributions (TMDs), and generalized parton distributions (GPDs) for the physical photon from the light-front quantum electrodynamics (QED) Hamiltonian, determined for…
A status report is given of some recent theoretical and experimental investigations looking for signals of Lorentz violation in QED. Experiments with light, charged particles, and atoms have exceptional sensitivity to small shifts in energy…
This article reviews our present understanding of QCD spin physics: the proton spin puzzle and new developments aimed at understanding the transverse structure of the nucleon. We discuss present experimental investigations of the nucleon's…
Various aspects of physics at LEP 2 are reviewed from a phenomenological point of view. We first discuss the search for Higgs bosons, which might be relatively light if indications from the precision electroweak data and supersymmetry are…
Recent advances in lattice field theory, in computer technology and in chiral perturbation theory have enabled lattice QCD to emerge as a powerful quantitative tool in understanding hadron structure. I describe recent progress in the…
It is shown that by assuming Gribov factorization to hold at low $x$ one obtains a simple relation between the structure function of the proton and that of the photon. By interpreting an observed structure in deep inelastic scattering (DIS)…
Proton imaging has become a key diagnostic for measuring electromagnetic fields in high-energy-density (HED) laboratory plasmas. Compared to other techniques for diagnosing fields, proton imaging is a non-perturbative measurement that can…
Since the current uncertainty on the structure of the proton affects the new physics discovery potential of LHC, the ATLAS collaboration is investigating methods to constrain this uncertainty over the whole LHC kinematic regime. The…
We have studied the pion^{-} capture in nuclei leading to two photons, using improved many body methods which have been tested with success in one photon pion^{-} radiative capture, muon^{-} capture and neutrino scattering. The qualitative…
We employ new field-theoretical tools to study photons and jets in a non-equilibrium quark-gluon plasma. Jet broadening and photon emission takes place through radiation which is suppressed by repeated and coherent interaction with the…
This is a summary of experimental results on photons, leptons, and heavy quarks presented at Quark Matter 2008. A first measurement of the bottom to charm contribution to the lepton spectrum has given experimental indication for the…
The subject of lepton-hadron scattering is discussed from its earliest beginnings, concentrating on what we have learnt from the HERA electron-proton storage ring. A brief selection of the HERA I results most relevant to LHC are discussed.…
Studies of hadronic final states of $e^+e^-$ annihilations at LEP are reviewed. The topics included cover hadronic event shapes, measurements of $\alpha_s$, determinations of QCD colour factors and tests of the non-Abelian gauge structure…
We demonstrate that a future high-energy electron-proton collider like THERA could largely extend the current HERA program in jet photoproduction of testing QCD and determining the partonic structure of the proton and the photon. Depending…
Muon pair production in the process e+e- -> e+e-mu+mu- is studied using the data taken at LEP1 (sqrt(s) \simeq m_Z) with the DELPHI detector during the years 1992-1995. The corresponding integrated luminosity is 138.5 pb^{-1}. The QED…
We discuss QCD studies that will be possible at LEP2. We examine both experimental and theoretical aspects of jets, fragmentation functions, multiplicities and particle spectra.
We investigate the effects of photon radiation on deep-inelastic $\re\gamma$ scattering. Depending on the set of variables chosen, we find appreciable effects in the kinematic region accessible at LEP2. Convenient analytic results for…
The implications of the positivity constraint on the presently unknown polarized structure function of the photon, $g_1^{\gamma}(x,Q^2)$, are studied in detail. In particular the non-trivial consequences of this constraint,…