Showing papers by "Antonio Ereditato published in 1994"
TL;DR: In this paper, the electroweak parameters from neutrino-neutrino electron scattering were analyzed in the C H A R M II detector from 1987 to 1991, and the results showed that the effective vector and axial-vector neutral current coupling constants were at least 0.2324 4-0.0083 and 0.017, respectively.
204 citations
15 Sep 1994-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the construction of modules and the assembly of the calorimeter for CHORUS, an experiment that searches for ν μ ↔ ν τ oscillation, have been completed.
Abstract: The construction of modules and the assembly of the calorimeter for CHORUS, an experiment that searches for ν μ ↔ ν τ 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 /∼30%/√ 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.
42 citations
01 Jan 1994-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, an experimental study of the properties of a modular lead/scintillating-fiber calorimeter with a fully projective tower geometry is presented. But the results are limited to the case of pion showers only partially contained in the detector.
Abstract: We report on an experimental study of the properties of a modular lead/scintillating-fiber calorimeter with a fully projective tower geometry. Although the calorimeter structure is monolythic, an effective segmentation into an electromagnetic and an hadronic section is achieved by separating the readout of the fibers running throughout the calorimeter from those starting beyond a depth of ∼ 25 radiation lengths. This feature is used for e/ π separation. Discontinuities in the sampling fraction near the boundaries of the modules cause a signal nonuniformity for electrons, which can be corrected. Similar effects observed for high energy hadrons are discussed. Results are given on the energy and position resolution for electrons, on the signal linearity and on the absolute light yield. Pion showers were only partially contained in this detector. The information from a backing calorimeter, consisting of fast thin-gap wire chambers interleaved by iron slabs, significantly improves the energy resolution of the incompletely contained pion showers.
14 citations
TL;DR: In this article, the first experimental result of the coupling of the muon neutrino with the Z was reported, which was in good agreement with the average value of the three neutrinos families as derived from the invisible decay width of the Z.
13 citations
01 Jan 1994-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, an experimental study of the performance of an electromagnetic calorimeter consisting of thin (0.5 mm diameter) scintillating plastic fibers embedded in lead is presented.
Abstract: We report on an experimental study of the performance of an electromagnetic calorimeter consisting of thin (0.5 mm diameter) scintillating plastic fibers embedded in lead. Because of the small sampling fraction (3.5% for minimum ionizing particles), this detector is quite compact, with an effective radiation length of 7.2 mm and a Moliere radius of 20 mm. Because of the very frequent shower sampling provided by the fibers, the energy resolution is nevertheless good: 9.2%/√E(GeV) for electromagnetic (e.m.) showers, with a small, angle dependent constant term. A non-uniformity in the response is observed at the 2% level across the calorimeter. In spite of the small sampling fraction the light yield is not a limiting factor in this calorimeter: we measured ∼ 500 photoelectrons per GeV shower energy. The position resolution for electrons and two e.m. showers separation have been studied. The fibers sticking out of the back of the detector do not appear to affect the measurements of hadronic showers.
11 citations
TL;DR: In this article, the existence of additional Z bosons derived from neutrino-electron scattering data was analyzed based on data taken by the CHARM II Collaboration during five years of exposure of the detector to the wide band neutrinos beam at CERN.
8 citations
TL;DR: In this article, a search for νμ → νe and\(\bar
u _\mu \to \bar �nu _e \) oscillations has been carried out with the CHARM II detector exposed to the CERN wide band neutrino beam.
Abstract: A search for νμ → νe and\(\bar
u _\mu \to \bar
u _e \) oscillations has been carried out with the CHARM II detector exposed to the CERN wide band neutrino beam. The data were collected over five years, alternating beams mainly composed of muon-neutrinos and muon-antineutrinos. The number of interactions of νe and\(\bar
u _e \) observed is comparable with the number of events expected from flux calculations. For large squared mass differences the upper limits obtained on the mixing angle aresin22θ < 9.4 · 10−3 for νμ oscillating to νe andsin22θ < 4.8 · 10−3 for\(\bar
u _\mu \) to\(\bar
u _e \), at the 90% confidence level. Combining neutrino and antineutrino data the upper limit is 5.6 · 10−3.
8 citations
21 Apr 1994-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The CHORUS Collaboration is presently building a new detector for the search of ν μ - ν τ oscillations in the CERN neutrino beam, the experiment being sensitive to a mixing angle an order of magnitude smaller than the present limit as discussed by the authors.
Abstract: The CHORUS Collaboration is presently building a new detector for the search of ν μ - ν τ 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.
1 citations
21 Aug 1994-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the authors report on the design and performance of a new instrument for the high-statistics measurement of the fiber properties, in terms of light yield and light attenuation length.
Abstract: There is today widespread use of plastic scintillating fibers in particle physics, mainly for calorimetric and tracking applications. In the case of calorimeters, we have to cope with very massive detectors and a large quantity of scintillating fibers. The CHORUS Collaboration has built a new detector to search for νμ-ντ oscillations in the CERN neutrino beam. A crucial task of the detector is ruled by the high-energy resolution calorimeter. For its construction more than 400000 scintillating plastic fibers have been used. In this paper we report on the design and performance of a new instrument for the high-statistics measurement of the fiber properties, in terms of light yield and light attenuation length. The instrument has been successfully used to test about 3% of the total number of fibers before the construction of the calorimeter.