Speaker
Description
COMPASS final results on multiplicities of charged hadrons,
pions and kaons, produced in the deep inelastic muon scattering
off an isoscalar target will be presented. Measurements were
taken in bins of x,y and z in a wide kinematic range.
The hadron and pion data show a good agreement
with (N)LO expectations and some of the
preliminary measurements have been already incorporated
in the global NLO fits to the world data.
The pion multiplicity results were used to
extract the LO quark fragmentation functions.
The most interesting are kaon multiplicities allowing to extract kaon
fragmentation functions, crucial in solving the strange quark
polarisation puzzle. The COMPASS results are quite different from the
expectations of the NLO DSS fit; nor they can be described by the LO QCD.
In this context the importance of K+/K- multiplicity ratio
at high z will be discussed.
