Related papers: The photon structure function measurements from LE…
A summary is given on the main aspects which were discussed by the working group. They include new results on the deep inelastic scattering structure functions $F_2, xF_3, F_L$ and $F_2^{c\bar{c}}$ and their parametrizations, the…
An introduction and summary is given of the main results achieved by working group 1: Structure Functions in Deep Inelastic Scattering at HERA. The prospects were discussed of future measurements of the structure functions $F_{2}, F_{L},…
The organization of finite order QCD approximations to $F_2^{\gamma}(x,Q^2)$ based on the separation of pure QED contribution from those of genuine QCD nature is discussed.
In recent years the investigation of hadron structure using lattice techniques has attracted growing attention. In this talk we give an overview on recent work with a focus on results for nucleon spectrum and structure from the QCDSF…
The virtual photon structure function $g_1^{\gamma}(x,Q^2,P^2)$, which can be obtained in polarized $e^{+}e^{-}$ colliding-beam experiments, is investigated for $\Lambda^2 \ll P^2 \ll Q^2$, where $-Q^2$ ($-P^2$) is the mass squared of the…
The parametrisation of the photon structure function in the low Q^2 region is formulated. It includes the VMD contribution and the QCD improved parton model component suitably extrapolated to the low Q^2 region. The parametrisation…
We investigate the effects of gluon number fluctuations on the total $\gamma\gamma$, $\gamma^*\gamma^*$ cross sections and the photon structure function $F_2^\gamma(x,Q^2)$. Considering a model which relates the dipole-dipole and…
The inclusive production of prompt photons with energy above 10 GeV is measured using the OPAL detector in hadronic Z^0 decays at LEP. In contrast to previous measurements, the prompt photons were not required to be isolated. The production…
We review some selected recent results on hadron spectroscopy and related theoretical studies based on constituent quark models.
In the Standard Model the process e+e- -> gamma-gamma is fully described by QED. Measurements of the differential cross-sections from the four LEP experiments are compared to the QED expectation and limits are set on parameters describing…
We present the structure function ratios F2(Li)/F2(D) and F2(C)/F2(D) measured in deep inelastic muon-nucleus scattering at a nominal incident muon energy of 200 GeV. The kinematic range 0.0001 < x < 0.7 and 0.01< Q^2 < 70 GeV^2 is covered.…
An overview is given of the ongoing measurement at HERA of the parton structure of the photon, as a function of its virtuality. Preliminary ZEUS results show disagreement with an NLO QCD calculation.
QCD predictions on the low-$x$ behaviour of the structure functions are reviewed and compared with the recent measurements of $F_2(x,Q^2)$ at HERA. The present theoretical accuracy of these predictions is discussed.
The current status of measurements of the nucleon structure functions and their understanding is reviewed. The fixed target experiments E665, CCFR and NMC and the HERA experiments H1 and ZEUS are discussed in some detail. The extraction of…
We investigate the virtual photon structure function in the supersymmetric QCD (SQCD), where we have squarks and gluinos in addition to the quarks and gluons. Taking into account the heavy particle mass effects to the leading order in QCD…
Latest results on structure functions, as available at the Lepton-Photon Symposium 1999, are presented. This report focusses on three experimental areas: new structure function measurements, in particular from HERA at low x and high Q2;…
The spin-averaged structure function of the neutron, F_2^n, is extracted from recent deuteron data, taking into account the small but significant corrections due to nuclear effects in the deuteron. At small x, the F_2D/F_2p ratio measured…
We compare new HERA data for the longitudinal structure function $F_{\rm L}$ with the predictions of different variants of the dipole model. In particular we show that the ratio $F_{\rm L}/F_2$ is well described by the dipole models and is…
The electromagnetic and weak structure functions of the photon can be studied in the deep inelastic electron-photon processes e+gamma -> e+X and e+gamma -> nu+X. While at low energies only virtual photon exchange is operative in the…
Two-photon processes in electron-positron collisions of the form $e^+e^-\to e^+e^-X$ are a well-established tool for probing hadronic structure and provide a direct access to non-vector states in $e^+e^-$ collisions. Collisions of quasi…