Gluon Polarisation in the Nucleon from COMPASS

New results on the longitudinal inclusive asymmetry $A^{d}_{1}$ and the spin-dependent structure function $g^{d}_{1}$ is the range 0.002 (GeV/c)$^{2} < Q^{2} <$ 100 (GeV/c)$^{2}$ and 0.00004 $< x <$ 0.7 and new measurements of the gluon polarization $\Delta G/G$ via the open charm channel and based on the helicity asymmetry of large transverse-momentum hadrons in the final state are presented. The data have been collected in the years 2002-2004 by the COMPASS experiment at CERN using a 160 GeV/c polarized muon beam scattered off a polarized $^{6}$LiD target. The longitudinal asymmetry results in the low $x$ (0.00004 $< x <$ 0.03) and low $Q^{2}$ (0.002 (GeV/c)$^{2} < Q^{2} <$ 1 (GeV/c)$^{2}$) region are consistent with zero and the precision increased ten times compared to the results of the SMC, so far the only experiment which has measured the low $x$ and low $Q^{2}$ domain. The results on the spin-dependent structure function $g^{d}_{1}$ measured in DIS region ($Q^{2} >$ 1 (GeV/c)$^{2}$) are in agreement with those from previous experiments, improve considerable the statistical accuracy for 0.004 $< x <$ 0.03 region and have been included in new COMPASS NLO QCD analysis of the world data. The new preliminary result for $\Delta G/G$ from the charm channel is $-$0.57$\pm$ 0.41$(stat.)$ at $x_{G}\simeq$ 0.15 and scale $\mu^{2}\simeq$ 13 (GeV/c)$^{2}$. The gluon polarization from high-$p_{T}$ hadron pairs is $\Delta G/G =$ 0.016 $\pm$ 0.058$(stat.) \pm$ 0.055$(syst.)$ at $x_{G}\simeq$ 0.085$^{0.07}_{0.035} (Q^{2} <$ 1 (GeV/c)$^{2}$ and $\mu^{2}\simeq$ 3 (GeV/c)$^{2}$).