Related papers: An Experimenter's Highlights
Glueballs are the most straightforward prediction of QCD, yet while they have likely been produced, none has been unequivocally identified. We pursue a backdoor approach through anomalies, and singularly the $\eta$ and $\eta$' which brings…
Recent results on spectroscopy with special focus on searches for pentaquarks are presented from the H1 and ZEUS collaborations. Cross sections of observed states and upper limits on the production cross section of unobserved states are…
Data taken with the ALEPH detector at LEP1 have been used to search for gamma gamma production of the glueball candidates f0(1500) and fJ(1710) via their decay to pi+pi-. No signal is observed and upper limits to the product of gamma gamma…
The status of HERA data on jet photoproduction is reviewed, and some suggestions and prospects for further work are given.
A selection of results from the H1 and ZEUS experiments at HERA are reviewed, particularly in the area of deep inelastic scattering and diffraction. Quantum chromodynamics gives a good explanation of these data down to surprisingly low…
The results are presented of a study of the accuracy one may achieve at HERA in measuring the strong coupling constant $\alpha_s$ and the gluon distribution $xg(x,Q^{2})$ using future data of the structure function $F_{2}(x,Q^{2})$ which…
The present status of Unified Theories is summarized with special emphasis on their possible experimental tests. Outline: i) Unification of couplings; ii) Where can a positive signal come from? iii) HERA anomaly and Unification; iv) Recent…
We point out a few remarkable properties of the $\gamma\gamma\to\gamma\gamma$ process at high energy. They should allow to search for effects of new particles and interactions. We give illustrations with threshold effects due to pairs of…
In this report on Photon Colliders the following technical aspects are considered: special requirements to an accelerator, new ideas on laser optics, laser cooling, and interaction region layout issues. In fact it is continuation of my…
We summarize the work done in the ``Beyond the Standard Model'' group of the 1995-96 HERA Workshop. Of the various proposed HERA upgrades, the luminosity improvement is the most important for this physics. With an integrated luminosity of 1…
Some selected topics in photoproduction are reviewed. In particular, the focus is on quasi-real photon-proton scattering as measured at HERA. Single & dijet rates and jet profiles are discussed, as are open charm production and inelastic…
There are few data available with which to constrain the thermal history of the intergalactic medium (IGM) following global recombination. Thus far, most constraints flow from analyses of the Cosmic Microwave Background and optical…
The report from the working group on '\gamma\gamma Event Generators' of the LEP 2 workshop
Multiple interaction models satisfying $s$-channel unitarity predict that, in contrast to inelastic processes, factorization is violated in diffractive processes. The size of this effect can be characterized in terms of the rapidity gap…
Recent results on charm fragmentation and hadron spectroscopy in $e^+/e^- p$ collisions at HERA with the ZEUS and H1 detectors are presented. The measured fragmentation ratios and fragmentation fractions are in agreement with those measured…
We examine HERA data with a view of determining whether unique signs of saturation can be identified. Concentrating on two channels the logarithmic slope of $F_{2}$, and the production of $J/\Psi$, which are sensitive to the behaviour of…
The focus of this presentation is to go through some of the remarkable observations concerning gamma-ray cosmic accelerators and diffuse emissions. Additionally, I will cover the status of the new generation of gamma-ray groundbased…
Recent results of searches for leptoquarks, lepton flavour violating leptoquarks and excited fermions (electrons, neutrinos and quarks) with the H1 experiment at HERA are presented, which use up to the full ep H1 data set. No evidence for…
Various jet observables in photoproduction are studied and compared to data from HERA. The feasibility of using a dijet sample for constraining the parton distributions in the photon is then studied. For the current data the experimental…
Measurements of diffractive phenomena observed at HERA are reviewed. A short introduction to the theoretical background is presented. The review focuses on the current experimental directions and discusses the exclusive production of vector…