Related papers: The photon structure function measurements from LE…
At high energies photon-photon interactions are dominated by quantum fluctuations of the photons into fermion-antifermion pairs and into vector mesons. This is called photon structure. Electron-positron collisions at LEP are an ideal…
The QCD structure of the electroweak bosons is reviewed and the lepton structure function is defined and calculated. The leading order splitting functions of electron into quarks are extracted, showing an important contribution from…
The production of final state photons in hadronic $Z$-boson decays can be used to study the quark-to-photon fragmentation function $D_{q\to \gamma}(z,\mu_{F})$. Currently, two different observables are used at LEP to probe this function:…
Recent experimental results contributing to the understanding of the structure of the nucleon are reviewed. They include the final NMC results on proton and deuteron structure functions; a re-analysis of the CCFR data on F2 and xF3; new…
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…
Structure functions are a measure of the partonic structure of hadrons, which is important for any process which involves colliding hadrons. They are a key ingredient for deriving partons distributions in nucleons. In recent years dramatic…
In this talk I briefly explain the concept of the structure function of a photon (the best known boson). Then I review some of the current experimental evidence which confirms the existence of `strong' interactions of photon suggested by…
We present a fully analytic computation of the complete electron and photon structure functions, or QED lepton parton distribution functions (PDFs) up to two-loop order. Our computation is performed using modern techniques of reduction to…
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…
Achieving a precise description of the internal structure of hadrons is a hard task, since there are several bottlenecks to obtain theoretical predictions starting from first principles. In order to complement the highly-accurate…
We calculate the spin dependent structure function of the polarized virtual photon $g_1^{\gamma}(x,Q^2,p^2)$, especially its hadronic part, using the OPE in the inverse powers of the target photon virtuality. Some model is accepted to…
In the framework of the perturbative QCD we investigate heavy particle mass effects on the unpolarized and polarized photon structure functions, $F_2^\gamma$ and $g_1^\gamma$, respectively. We present our basic formalism to treat heavy…
We present a systematic analysis of the processes $e^+ ~e^- \rightarrow e^+ ~e^- X$ to study the polarised and unpolarised photon structure functions. The effect of target photon mass, which manifests itself as new singly polarised…
At HERA, the electron-proton collider at DESY, Hamburg, the large flux of almost on-shell photons accompanying the lepton beam is being used to shed new light on the structure of the photon. Recent results are reviewed and discussed, with…
The status of and ongoing developments in the measurements and theoretical studies of the structure of the photon have been presented at the PHOTON 2001 conference in Ascona. The results presented in the structure function session are…
We present our analysis on the photon structure functions at small Bjorken variable x in the framework of the holographic QCD. In the kinematic region, a photon can fluctuate into vector mesons and behaves like a hadron rather than a…
Recent measurements of unpolarised and polarised nucleon structure functions and F_2(gamma) are reviewed. The implications for QCD and the gluon momentum distribution are discussed. The status of the understanding of the total…
We present the first calculation of QED radiative corrections to deep-inelastic electron-photon scattering in terms of those variables that are reconstructed in measurements of the photon structure function in electron-positron collisions.…
We present the complete NLO QCD analysis of the photon structure functions $F_2^\gamma(x,Q^2)$ and $F_L^\gamma(x,Q^2)$ for a real photon target. In particular we study the heavy flavor content of the structure functions which is due to two…
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.