Leading order determination of the gluon polarisation from DIS events   with high-p_T hadron pairs
  We present a determination of the gluon polarisation Delta g/g in the nucleon, based on the longitudinal double-spin asymmetry of DIS events with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam scattering off a polarised ^6LiD target. The gluon polarisation is evaluated by a Neural Network approach for three intervals of the gluon momentum fraction x_g covering the range 0.04 < x_g < 0.27. The values obtained at leading order in QCD do not show any significant dependence on x_g. Their average is Delta g/g = 0.125 +/- 0.060 (stat.) +/- 0.063 (syst.) at x_g=0.09 and a scale of mu^2 = 3 (GeV/c)^2. 
C. Adolph, M.G. Alekseev, V.Yu. Alexakhin, Yu. Alexandrov, G.D.   Alexeev, A. Amoroso, A.A. Antonov, A. Austregesilo, B. Bad...
hep-ex