[en] The instrumented targets of the OPERA neutrino experiment are complemented by two massive spectrometers based on gapless iron magnets. In 2006, a systematic assessment of their electromagnetic properties have been carried out. In this document, we report the results of such characterization and demonstrate that the achieved performance fulfill the physics requirements for the study of ν_μ→ν_τ oscillations

[en] The design and construction of the 990-ton gapless iron magnets for the OPERA experiment represent a major challenge from the point of view of mechanics, electric and heat engineering. Two of such magnets have been built in a deep underground hall of the Gran Sasso laboratories between 2003 and 2006 and they have been switched on for the first time in March 2006. In this paper we discuss the construction and characterization of these devices. First experience with the CNGS beam are also reported

[en] A large-area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3GeV/c up to 8GeV/c for the CLAS12 experiment at the upgraded 12GeV continuous electron beam accelerator facility of Jefferson Laboratory. The adopted solution foresees a novel hybrid optics design based on aerogel radiator, composite mirrors and highly packed and highly segmented photon detectors. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large-angle tracks). We report here the results of the tests of a large-scale prototype of the RICH detector performed with the hadron beam of the CERN T9 experimental hall for the direct detection configuration. The tests demonstrated that the proposed design provides the required pion-to-kaon rejection factor of 1: 500 in the whole momentum range. (orig.)

[en] A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator facility of Jefferson Lab to study the 3D nucleon structure in the yet poorly explored valence region by deep-inelastic scattering, and to perform precision measurements in hadronization and hadron spectroscopy. The adopted solution foresees a novel hybrid optics design based on an aerogel radiator, composite mirrors and densely packed and highly segmented photon detectors. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large angle tracks). The preliminary results of individual detector component tests and of the prototype performance at test-beams are reported here. - Highlights: • A novel hybrid-optics configuration was proven to work with a large RICH prototype. • Innovative RICH components were studied both in laboratory tests and test-beams. • Aerogel of large Rayleigh scattering length at n=1.05 was characterized. • Novel vs commercially available multi-anode photomultipliers were compared. • The response of SiPM matrices to Cherenkov light was tested at various temperatures

[en] The DIRAC spectrometer has been commissioned at CERN with the aim of detecting π⁺π^- atoms produced by a 24 GeV/c high intensity proton beam in thin foil targets. A challenging apparatus is required to cope with the high interaction rates involved, the triggering of pion pairs with very detector efficiency.ation of the imaging sof the latter with resolution around 0.6 MeV/c. The general characteristics of the apparatus are explained and each part is described in some detail. The main features of the trigger system, data-acquisition, monitoring and set-up performances are also given

[en] The OPERA experiment will study ν_μ to ν_τ oscillations through τ appearance on the 732km long CERN to Gran Sasso baseline. The magnet yokes of the two muon spectrometers are instrumented with 48 planes of high resistivity bakelite Resistive Plate Chambers (RPC) operated in streamer mode. Each plane covers about 70m². A general introduction to the system installation and commissioning will be given. Four RPC planes were instrumented and the first tests were performed confirming a good behavior of the installed RPCs in terms of intrinsic noise and operating currents. The measured noise maps agree with those obtained in the extensive quality test performed at surface. Counting rates are below 20Hz/m². Single and multiple cosmic muon tracks were also reconstructed. The estimated efficiency is close to the geometrical limit and the very first measurements of the absolute and differential muon flux are in agreement with the expectations. Finally, a description of the readout electronics and of the slow control system is given

[en] P-bar ANDA is a new experiment that will be installed at HESR, the new antiproton storage ring under construction as a part of the FAIR facility at Darmstadt, Germany. This experiment, that will investigate QCD in the charmonium mass regime and other aspects of particle and nuclear physics, will be a fixed target detector with a central spectrometer and a forward one. The central tracker will provide information about decay vertices, momenta and types of charged particles emitted after pp-bar annihilations. The design of the Straw Tube Tracker (STT) together with experimental results of the R and D phase are presented here.

[en] The NESSiE Collaboration has been setup to undertake a conclusive experiment to clarify the muon-neutrino disappearance measurements at short baselines in order to put severe constraints to models with more than the three-standard neutrinos. To this aim the current FNAL-Booster neutrino beam for a Short-Baseline experiment was carefully evaluated by considering the use of magnetic spectrometers at two sites, near and far ones. The detector locations were studied, together with the achievable performances of two OPERA-like spectrometers. The study was constrained by the availability of existing hardware and a time-schedule compatible with the undergoing project of multi-site Liquid-Argon detectors at FNAL. The settled physics case and the kind of proposed experiment on the Booster neutrino beam would definitively clarify the existing tension between the ν_μ disappearance and the ν_e appearance/disappearance at the eV mass scale. In the context of neutrino oscillations the measurement of ν_μ disappearance is a robust and fast approach to either reject or discover new neutrino states at the eV mass scale. We discuss an experimental program able to extend by more than one order of magnitude (for neutrino disappearance) and by almost one order of magnitude (for antineutrino disappearance) the present range of sensitivity for the mixing angle between standard and sterile neutrinos. These extensions are larger than those achieved in any other proposal presented so far. (orig.)