We report the results of measurements performed using a tracking detector based on 835 μm scintillating fibres read out by two position-sensitive photomultipliers. A six-layer hodoscope consisting of ...1.2 m long fibres has been built and tested using cosmic rays. Subsequently, two such hodoscopes have been assembled and tested using a hadron beam at the CERN PS. The efficiency per plane is found to be about 70% and the point resolution about 130 μm. The signal-to-noise ratio is about 2.4 and is dominated by crosstalk in the position-sensitive photomultipliers.
We present a study of exclusive neutral pion production in neutrino-nucleus Neutral Current interactions using data from the NOMAD experiment at the CERN SPS. The data correspond to 1.44×106 ...muon-neutrino Charged Current interactions in the energy range 2.5⩽E⩽300 GeV. Neutrino events with only one visible π0 in the final state are expected to result from two Neutral Current processes: coherent π0 production, ν+A→ν+A+π0 and single π0 production in neutrino-nucleon scattering. The signature of coherent π0 production is an emergent π0 almost collinear with the incident neutrino while π0's produced in neutrino-nucleon deep inelastic scattering have larger transverse momenta. In this analysis all relevant backgrounds to the coherent π0 production signal are measured using data themselves. Having determined the backgrounds, and using the Rein-Sehgal model for the coherent π0 production to compute the detection efficiency, we obtain 4630±522(stat)±426(syst) corrected coherent-π0 events with E⩾0.5 GeV. We measure σ(νA→νAπ0)=72.6±8.1(stat)±6.9(syst)×10-40 cm2/nucleus. This is the most precise measurement of the coherent π0 production to date.
We present a measurement of the muon neutrino nucleon inclusive charged current cross section, off an isoscalar target, in the neutrino energy range 2.5⩽E⩽40 GeV. The significance of this measurement ...is its precision, ±4% in 2.5⩽E⩽10 GeV, and ±2.6% in 10⩽E⩽40 GeV regions, where significant uncertainties in previous experiments still exist, and its importance to the current and proposed long baseline neutrino oscillation experiments.
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