Tests of a scintillating-fibre tracking detector based on position-sensitive photomultiplier readout

We report the results of measurements performed using a tracking detector based on 835 mu m 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 mu m. The signal-to-noise ratio is about 2.4 and is dominated by crosstalk in the position-sensitive photomultipliers

Measurement of the spin structure of the deuteron in the DIS region

Ageev ES, Alexakhin VY, Alexandrov Y, et al. Measurement of the spin structure of the deuteron in the DIS region. Phys.Lett. B. 2005;612(3-4):154-164.We present a new measurement of the longitudinal spin asymmetry Ad and the spin-dependent structure function g(1)(d) of the deuteron in the range 1 < Q(2) < 100 GeV2 and 0.004 < x < 0.7. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarised muon beam and a large polarised (LiD)-Li-6 target. The results are in agreement with those from previous experiments and improve considerably the statistical accuracy in the region 0.004 < x < 0.03. (c) 2005 Elsevier B.V. All rights reserved