On a Possibility to Determine the Sign of the Polarized Gluon Distribution

We investigate the possibility to draw conclusions on the sign of the spindependent gluon distribution, ∆G(x,Q), from existing polarized DIS data. The spin-dependent parton distributions ∆uv,∆dv ,∆ū,∆d̄,∆s, and ∆G are constructed in the framework of a phenomenological procedure taking into account some assumptions on signs of valence and sea parton distributions motivated by ’t Hooft’s mechanism of quark-quark interaction induced by instantons. The axial gluon anomaly and data on integral quark contributions to the proton spin, ∆ũ,∆d̃, and ∆s̃, are also taken into account. Predictions for the xand Q-dependencies of the polarized proton and neutron structure functions, g 1 and g n 1 , are compared to experimental data. It is shown that the neutron structure function, g 1 , is especially sensitive to the sign of ∆G(x,Q). The results of our analysis supports the conclusion that this sign should be positive.