[en] First results on the CDHS low energy nu oscillation experiment at the CERN PS are reported. The experiment looks for the disappearance of nu/sub μ/ measuring simultaneously the nu flux at 130 and 885 m distance from the target. No significant deviation from the expected flux ratio has been found. The experiment excludes therefore oscillations of the type nu/sub μ/ yields anything in the range 0.26 < DELTAm < 90 eV² for maximal mixing. The best limit on the mixing angle sin²2theta is 0.05 for DELTAm² approximately 2.5 eV²

[en] A summary of the present status of neutrino mass and neutrino oscillation experiments is given. Emphasis is put on the more recent claims of indications of a heavy (17.1 keV) neutrino and ν_μ → ν_e oscillations. None of these claims turns out to be convincing. In addition a large number of experiments is discussed not seeing any signs of mass or oscillations

[en] Results from the CDHS low energy ν oscillation experiment at the CERN PS are reported. The experiment looks for the disappearance of νsub(μ) measuring simultaneously the ν flux at 130 and 885 m distance from the target. No significant deviation from the expected flux ratio has been found. The experiment excludes therefore oscillations of the type νsub(μ) → anything in the range 0.26 < Δm < 90 eV² for maximal mixing. The best limit on the mixing angle sin²2theta is 0.05 for Δm² approximately equal 2.5 eV²

[en] The general conception of neutrino oscillations is shortly described and the review of present experimental results is given. However the obtained results are not convincing evidence for existence of neutrino oscillations nevertheless they throw some light on this phenomenon. The programs of future experiments in Brookhaven, Los Alamos and CERN are briefly presented. (I.L.)

No abstract available

[en] Since the 1980 conference a large number of results on structure functions have been reported from neutrino experiments. New data are available from ν and anti ν scattering on protons and neutrons. Measurements of the cross section ratios sigmasup(νn)/sigmasup(νp) as function of energy and scaling variables x and y allow the extraction of differences between the u- and d-quark momentum distributions. Final results on structure functions from ν experiments on isoscalar targets exhibit clearly scaling violations. QCD fits to the data yield values of the scale breaking parameter Λ = 0.1-0.2 GeV. From a new measurement of the Q² evolution of the antiquarks together with F₂ data the gluon x distribution has been extracted. The discrepancies in the measurement of the total cross section are still unresolved. (orig.)

[en] There is considerable interest in measuring the electroweak mixing parameter sin²θ_w of the Glashow-Salam-Weinberg theory as precisely as possible: first, its value may be predicted by models of Grand Unification; second, precise measurements of sin²θ_w from different processes would test the validity of electroweak radiative corrections. Different methods have been used to determine sin²θ_w over a large range of Q² values. Figure 1 gives a compilation of sin²θ_w with remarkable agreement between the results. At present, it is most precisely determined in semileptonic neutrino-nucleon scattering from the ratio of neutral current (NC) to charged current (CC) cross sections, and in proton-antiproton collisions from the W boson mass. Here, results are reported from an experiment of the first type. In order to achieve a higher precision in R_v = NC/CC than in previous experiments, the upgraded CDHS detector was exposed to an optimized version of the CERN narrow-band beam (NBB). This provided a significant increase in statistics and a reduction of the uncertainties related to the neutrino flux. Most of the experiment was performed with neutrinos because the antineutrino NC/CC ratio is less sensitive to sin²θ_w

[en] Micromegas detectors show very good performance for charged particle tracking in high rate environments as for example at the LHC. It is shown that two coordinates can be extracted from a single gas gap in these detectors. Several micromegas chambers with spark protection by resistive strips and two-dimensional readout have been tested in the context of the R and D work for the ATLAS Muon System upgrade.

[en] Large-area particle detectors based on the bulk-micromegas technology are an attractive choice for the upgrade of LHC detectors and/or detectors for the ILC or other experiments. In the context of the R and D for the ATLAS Muon System upgrade, we have built detectors of order 1 m². In order to overcome the spark problem in micromegas a novel protection scheme using resistive strips above the readout electrode has been developed. This technology has undergone extensive tests with hadron beams at the CERN-SPS, X-rays in the lab, as well as in a neutron beam. In addition, four 10 × 10 cm² micromegas chambers have been installed in the ATLAS cavern and are taking data under LHC conditions. We will discuss the underlying design of the chambers and present results on the performance of these chambers.

[en] The time-of-flight system based on thin-gap glass resistive plate chambers (RPCs) for the HARP detector at CERN is described and first experience with the chamber operation and performance is reported. The system consists of 46 chambers, covers an area of 10 m² and has 368 readout channels. The chambers are 2 m long, 150 mm wide, and 10 mm thick and have four gas gaps of 0.3 mm each, the glass plates are 0.7 mm thick. The RPCs are operated in avalanche mode with a mixture of 90% C₂F₄H₂, 5% SF₆, and 5% C₄H₁₀