Speaker
Description
The talk will include the summary of COMPASS measurements of gluon polarisation in the nucleon and the final results concerning the spin dependent structure function g1. In order to improve flavour-by-flavour knowledge of the spin structure of the nucleon the so called semi-inclusive measurements of hadron asymmetries were performed. To fully profit from these measurements a more precise knowledge of fragmentation functions is needed. In view of this COMPASS recent results concerning pion and kaon multiplicity will be discussed. Besides a global overview of the COMPASS multiplicity data, special attention will be given to kaon production, in the cases where the kaon carries high energy fraction of the virtual photon energy. In this region, the multiplicity ratio of K+/K- obtained is much larger than the limit permitted by LO QCD.
