A new LO extraction of gluon polarisation from COMPASS DIS data

A new LO evaluation of the gluon polarization in the nucleon i s presented. The COMPASS data from 2002-2006 years from DIS region were re-analysed and gl uon polarization was extracted using a so called all- p T method. In this new method gluon polarization and leading pr ocess asymmetry are extracted simultaneously from the same data s et using a Neural Network approach. Reduction of both systematic and statistical uncertaintie s by more than 50% is achived compared to the published result PLB 718 (2013) 922. The preliminary v alue of gluon polarization is ∆ g / g = 0 . 113 ± 0 . 038 ± 0 . 035 at average gluon momentum fraction x g = 0 . 10 and scale of μ 2 = 3 (GeV/ c ) 2