First Measurement of the Transverse Spin Asymmetries of the Deuteron in Semi-Inclusive Deep Inelastic Scattering

First measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarized 6-LiD target are presented. The data were taken in 2002 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins asymmetry turns out to be compatible with zero, as does the measured Sivers asymmetry within the present statistical errors.Comment: 6 pages, 2 figure

Gluon polarization in the nucleon from quasi-real photoproduction of high-p hadron pairs

We present a determination of the gluon polarization DeltaG/G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q2 < 1 (GeV/c)2, 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 polarized muon beam scattered on a polarized 6LiD target. The helicity asymmetry for the selected events is A/D = 0.002 \ub1 0.019(stat) \ub1 0.003(syst). From this value, we obtain in a leading-order QCD analysis DeltaG/G = 0.024 \ub1 0.089(stat) \ub1 0.057(syst) at xg = 0.095 and \u3bc2 ~ 3 (GeV/c)2