Gluon spin in a quark model

We compute the gluon polarization ΔG and the gluon total angular momentum Jg in the Isgur–Karl quark model. Taking into account self-interaction contributions, we obtain for both quantities a positive value of about 0.24 at the model scale μ02≃0.25 GeV2. This estimate is reasonably close to the expectation from polarized deep inelastic scattering analyses.