Direct estimate of the gluon polarization in the nucleon

We make a first crude direct estimate of the net gluon polarization in the proton, Delta G, combining data on the asymmetries in high-p(T) hadron production from the HERMES, SMC and COMPASS collaborations. Although these data sample a restricted range of x, they provide no hint that Delta G is large. Fixing the normalizations of different theoretical parametrizations using the hadron asymmetry data, we find typical central values of Delta G similar to 0.5, with uncertainties of similar magnitude. Values of Delta G >= 2 are disfavored by Delta chi(2) similar to 9 to 20, depending on the parametrization used.