The polarised valence quark distribution from semi-inclusive DIS

The semi-inclusive difference asymmetry Ah+−h−Ah+−h− for hadrons of opposite charge has been measured by the COMPASS experiment at CERN. The data were collected in the years 2002–2004 using a 160 GeV polarised muon beam scattered off a large polarised 6LiD target in the kinematic range 0.006