SPACE RESOLUTION OBTAINED WITH A HIGHLY SEGMENTED SCIFI EM CALORIMETER

During the setting up of the LEP-5 experiment, we tested a longitudinal SCIFI e.m. calorimeter, having a module cross area 25 x 25 mm2 and 12.5 x 12.5 mm2 for large and small modules respectively. The results were obtained with 10 and 50 GeV electrons, and concern the impact point resolution and the transverse distribution of the e.m. shower energy inside the calorimeter

Hidden Valley Higgs Decays in the ATLAS detector

Neutral particles with long decay paths and many particle decay final states represent, from an experimental point of view, a challenge both for the trigger and for the reconstruction capabilities of the ATLAS apparatus. For the purpose of exploring the challenges to the trigger posed by long-lived particles, the Hidden Valley scenario serves as an excellent setting. In this poster we present the results of a first study of ATLAS detector performance for some Hidden Valley processes with long-lived, neutral states that decay throughout the detector volume to multi heavy-flavor jets, mainly b-bbar

THE HIGH-RESOLUTION CALORIMETER OF THE CHORUS EXPERIMENT

The CHORUS Collaboration is presently building a new detector for the search of vμ−vτ oscillations on the CERN neutrino beam, this experiment being sensitive to a mixing angle an order of magnitude smaller than previous experiments. The basic components of the CHORUS “hybrid” detector are an active target made of nuclear emulsions (for the direct observation of the decay of τ-leptons), an air-core spectrometer with scintillating fiber tracking, a lead-scintillator (fibers and strips) calorimeter (with μ-tracking provided by planes of limited streamer tubes) and a muon spectrometer, consisting of iron toroids and drift chambers. We report here on the design of the calorimeter and on the tests performed on prototype modules

The High-resolution Calorimeter of the Chorus Experiment

The CHORUS Collaboration is presently building a new detector for the search of nu(mu)-nu(tau) oscillations on the CERN neutrino beam, this experiment being sensitive to a mixing angle an order of magnitude smaller than previous experiments. The basic components of the CHORUS ''hybrid'' detector are an active target made of nuclear emulsions (for the direct observation of the decay of tau-leptons), an air-core spectrometer with scintillating fiber tracking, a lead-scintillator (fibers and strips) calorimeter (with mu-tracking provided by planes of limited streamer tubes) and a muon spectrometer, consisting of iron toroids and drift chambers. We report here on the design of the calorimeter and on the tests performed on prototype modules

CONSTRUCTION AND TEST OF MODULES OF THE CHORUS CALORIMETER

The CHORUS Collaboration is presently building a new detector for the search of nu(mu)-nu(tau) oscillations in the CERN neutrino beam, the experiment being sensitive to a mixing angle an order of magnitude smaller than the present limit. The basic components of the CHORUS ''hybrid'' detector are an active target made of nuclear emulsions, an air core spectrometer with scintillating fiber tracking, a high resolution calorimeter and a muon spectrometer. An account is given here of the design of the 110-tons compensating calorimeter, made of 1 mm diameter scintillating fibers embedded in a lead matrix, and of the test results from the first modules produced

CONSTRUCTION AND TEST OF CALORIMETER MODULES FOR THE CHORUS EXPERIMENT

The construction of modules and the assembly of the calorimeter for CHORUS, an experiment that searches for nu(mu) nu(tau) oscillation, have been completed. Within the experiment, the calorimeter is required to measure the energy of hadronic showers produced in neutrino interactions with a resolution of similar to 30%/root E(GeV). To achieve this performance, the technique, developed in recent years, of embedding scintillating fibers of 1 mm diameter into a lead matrix has been adopted for the most upstream part of the calorimeter. A more conventional system, of alternating layers of lead and scintillator strips, was used for the rest. Details of module construction as well as results obtained when modules were exposed to electron and muon beams are presented

Performance of the CHORUS Calorimeter with neutrino events

The CHORUS calorimeter is a large scale application of the lead-scintillating fibre calorimetry technique for high energy physics experiments. It uses 1450 km of fibres for a total calorimeter weight of 110 tons. We report here about the time stability of the scintillating fibres performances over five years of data taking in the CERN-WANF neutrino beam. The identification capability of particles produced in neutrino interactions is discussed. The identification algorithm is based on a neural network approach