Determination of the gluon polarisation in COMPASS experiment at CERN Original Research Article

Determining of the gluon polarisation in the nucleon, by measurement of the double spin asymmetry of the photon-gluon fusion process is the main goal of the COMPASS experiment at CERN. Experiment uses 160 GeV polarized muon beam and polarised 6LiD target. Photon-gluon fusion events are selected using charmed mesons and hadron pairs at large pT. Preliminary results on charm signal extraction, and spin asymmetry Aγ∗d of the cross sections for high pT hadron pairs production are presented.