Wavelength-shifting fibers for calorimetric measurements in a long base line neutrino oscillation experiment

Abstract The NOE Collaboration has proposed a calorimeter to measure the energy of the final states of ν interaction events. The properties of long scintillator bars with wavelength-shifting fiber readout have been studied to develop a calorimeter design option. Various prototypes have been exposed to a cosmic rays stand. The total measured light yield in the middle of a 6 m -long fiber is about 15 photoelectrons. With this photon collection performance, it has been simulated that the calorimeter can achieve 17%/ E and 50%/ E resolutions for electrons and pions, respectively

Finding New Genes for Non-Syndromic Hearing Loss through an In Silico Prioritization Study

At present, 51 genes are already known to be responsible for Non-Syndromic hereditary Hearing Loss (NSHL), but the knowledge of 121 NSHL-linked chromosomal regions brings to the hypothesis that a number of disease genes have still to be uncovered. To help scientists to find new NSHL genes, we built a gene-scoring system, integrating Gene Ontology, NCBI Gene and Map Viewer databases, which prioritizes the candidate genes according to their probability to cause NSHL. We defined a set of candidates and measured their functional similarity with respect to the disease gene set, computing a score () that relies on the assumption that functionally related genes might contribute to the same (disease) phenotype. A Kolmogorov-Smirnov test, comparing the pair-wise distribution on the disease gene set with the distribution on the remaining human genes, provided a statistical assessment of this assumption. We found at a p-value that the former pair-wise is greater than the latter, justifying a prioritization strategy based on the functional similarity of candidate genes respect to the disease gene set. A cross-validation test measured to what extent the ranking for NSHL is different from a random ordering: adding 15% of the disease genes to the candidate gene set, the ranking of the disease genes in the first eight positions resulted statistically different from a hypergeometric distribution with a p-value and a power. The twenty top-scored genes were finally examined to evaluate their possible involvement in NSHL. We found that half of them are known to be expressed in human inner ear or cochlea and are mainly involved in remodeling and organization of actin formation and maintenance of the cilia and the endocochlear potential. These findings strongly indicate that our metric was able to suggest excellent NSHL candidates to be screened in patients and controls for causative mutations

R&D results from the NOE scintillating fiber calorimeter

The development of the NOE calorimeter, based on scintillating fiber technology, has undergone four years of intense R&D activity. Measurements of light attenuation and time resolution have been carried out on a variety of commercially available scintillating fibers. Both these parameters are important for the optimization of the design of the NOE calorimeter. Experimental results on the fiber attenuation length and light yield make us confident on the possibility to build a 8 x 8 m(2) cross-section calorimeter without noticeable loss of signal. The time resolution is resulted to be of the order of 1 ns, sufficient for up/down discrimination in the final calorimeter setup, by means of the time-of-flight method. Several tests performed to optimize the elementary cell of the calorimeter are also described. (C) 2001 Elsevier Science B.V. All rights reserved

Wavelength-shifting fibers for calorimetric measurements in a long base line neutrino oscillation experiment

The NOE Collaboration has proposed a calorimeter to measure the energy of the final states of v interaction events. The properties of long scintillator bars with wavelength-shifting fiber readout have been studied to develop a calorimeter design option. Various prototypes have been exposed to a cosmic rays stand. The total measured light yield in the middle of a 6 m-long fiber is about 15 photoelectrons. With this photon collection performance, it has been simulated that the calorimeter can achieve 17%/rootE and 50%/rootE resolutions for electrons and pions, respectively. (C) 2001 Elsevier Science B.V. All rights reserved

A transition radiation detector interleaved with low-density targets for the NOE experiment

The NOE Collaboration has proposed a transition radiation detector (TRD) interleaved with marble targets to tag the electron decay channel of tau leptons produced by v(tau), eventually originated by upsilon (mu) oscillations in a long base line experiment. A reduced scale TRD detector prototype has been built and exposed to an electron/pion beam at the CERN PS. Discrimination capabilities between electrons and both charged and neutral pions, representing the main source of background for our measurement, have been determined obtaining rejection factors of the order of the tenth of percent for charged pions, and of a few percent for the neutral pion, matching the experiment requirements. The capabilities of this detector to measure the energy released by particles that start showering inside the targets are shown, A momentum resolution sigma (p)/p less than or equal to 40% is found for muons in the range of 1-7 GeV/c. (C) 2001 Elsevier Science B.V. All rights reserved

The NOE scintillating fiber calorimeter prototype test results

An intense R&D program has been carried out by the NOE Collaboration during the last years, to develop a massive fine grain scintillating fiber calorimeter, to be used, in combination with an appropriate target, in a Long Base Line experiment at the CERN to Gran Sasso (CNGS) neutrino beam. The performance of a 4 ton NOE calorimeter prototype exposed to a test beam at CERN PS is shown. Results on the linearity, electromagnetic and hadronic energy resolution are reported and compared with the Monte Carlo predictions. (C) 2001 Elsevier Science B.V. All rights reserved

The NOE scintillating fiber calorimeter prototype test results

An intense R&D program has been carried out by the NOE collaboration during the last years, to develop a massive fine grain scintillating fiber calorimeter, to be used, in combination with an appropriate target, in a long base line experiment at the CERN to Gran Sasso (CNGS) neutrino beam. The performance of a 4 ton NOE calorimeter prototype exposed to a test beam at CERN PS is shown. Results on the linearity, electromagnetic and hadronic energy resolution are reported and compared with the Monte Carlo predictions. (13 refs)