Spin physics - longitudinal

A short review of the COMPASS results obtained in polarized deep inelastic scattering of polarized muons off longitudinally polarized proton and deuteron targets is given. Two new measurements of the gluon polarization $\Delta G / G$ are discussed. A new LO result from the analysis of high-$p_{T}$ hadron pairs for $Q^{2}$ > 1 (GeV/c)$^{2}$ and separated into three experimental points as a function of $x_{G}$ is shown. A new open charm value for $\Delta G / G$ obtained at NLO, and which combines both proton and deuteron data and includes several $D^{0}$ decay channels is presented. Finally results for the LO flavor separation of the three lightest quark polarized parton distributions and charged $\pi$ and K multiplicities are shown.