Longitudinal double-spin asymmetries of charged hadrons with high transverse momentum p T have been measured in electroproduction using the H ermes detector at H era . Processes involving gluons in the nucleon have been enhanced relative to others by selecting hadrons with p T typically above 1 GeV. In this kinematic domain the gluon polarization has been extracted in leading order making use of the model embedded in the Monte Carlo Generator P ythia 6.2. The gluon polarization obtained from single inclusive hadrons in the p T range 1 GeV < p T < 2.5 GeV using a deuterium target is Δ g/g( ⟨ x ⟩, ⟨μ^2⟩) = 0.049± 0.034( stat)± 0.010( sys-exp)_ - 0.099^ + 0.126( sys-models) at a scale ⟨μ^2⟩ = 1.35 GeV^2 and ⟨ x ⟩ = 0.22 . For different final states and kinematic domains, consistent values of Δ g/g have been found within statistical uncertainties using hydrogen and deuterium targets.
