Measurement of the gluon polarization in the nucleon via spin asymmetries of charmed mesons at COMPASS

This article discusses a measurement of the gluon polarization in the nucleon, $\Delta g/g$. It concentrates on the most direct and cleanest way, the measurement of double spin asymme- tries of charmed mesons produced in deep inelastic muon-nucleon scattering. The method, the experimental set-up and the analysis leading to the result $\frac{\Delta g}{g} = −$0.39 $\pm$ 0.24(stat.) $\pm$ 0.11(syst.) at an average gluon momentum fraction $x_{g}\approx$ 0.11 and a scale $\mu^{2}\approx$ 13 GeV$^{2}$ are presented.