Measurement of the gluon polarization ΔG/G at COMPASS

One of the key objectives of the COMPASS experiment at CERN is the determination of the gluon contribution to the nucleon spin. The gluon polarization is measured via photon-gluon fusion in deep-inelastic scattering of 160 GeV/c polarized muons on a polarized (LiD)-Li-6 solid-state target. Photon-gluon fusion is tagged by the observation of charmed mesons or the production of hadron pairs with large transverse momenta p(t). The status of the analysis of the D-0 and D-0* events and of the high-p(t) hadron pairs is shown. The gluon polarization Delta G/G has been determined from the asymmetry of high-p, hadron pairs with Q(2) > 1 (GeV/c)(2) in an analysis of the 2002/03 data as Delta G/G = 0.06 +/- 0.31(stat.) +/- 0.06(syst.).