NEXT-TO-LEADING ORDER SEMIINCLUSIVE SPIN ASYMMETRIES

We have computed semi-inclusive spin asymmetries for proton and deuter on targets including next to leading order (NLO) QCD corrections and c ontributions coming from the target fragmentation region. These correc tions have been estimated using NLO fragmentation functions, parton di stributions and also a model for spin dependent fracture functions whi ch is proposed here. We have found that NLO corrections are small but non-negligible in a scheme where gluons are polarised and that our est imate for target fragmentation effects, which is in agreement with the available semi-inclusive data, does not modify significantly charged asymmetries but is non negligible for the so called difference asymmet ries.