Polarised parton densities from the fits to the deep inelastic spin asymmetries on nucleons

We have updated our next to leading order QCD fit for polarised parton densities [S. Tatur, J. Bartelski, M. Kurzela, Acta Phys. Pol. B31, 647 (2000)] using recent experimental data on the deep inelastic spin asymmetries on nucleons. Our distributions have functional form inspired by the unpolarised ones given by MRST (Martin, Roberts, Stirling and Thorne) fit. In addition to usually used data sample (averaged over variable Q(2) for the same value of x variable) we have also considered the points with the same x and different Q(2). Our fits to both groups of data give very similar results with substantial antiquark contribution in the measured region of x. In the first case we get rather small (DeltaG = 0.31) gluon polarisation. For the non averaged data the best fit is obtained when gluon contribution vanishes at Q(2) = 1 GeV2. Our new parametrisation of parton densities and additional experimental data taken into account do not change much our previous results.