Fragmentation functions of nonstrange quarks and diquarks

The fragmentation functions of nonstrange quarks and diquarks into various hadrons are analyzed making use of the data on inclusive spectra of charged pions and ρ0 mesons in νp and ν-barp interactions and assuming the hadronization process to be of recombination kind. Estimates are obtained for the parameters of the structure functions of quark-gluon systems, which are produced as a result of the pre-hadronization evolution of nonstrange quarks and diquarks. In particular, it is shown that in such systems ∼80% of the longitudinal momentum is carried away by gluons and sea quark-antiquark pairs, and ∼20% of the longitudinal momentum is associated with the leading or valence quarks. The pseudoscalar-to-vector meson yield ratio in the fragmentation range of nonstrange quarks is found to be AP/AV=1.5±0.3. Various models of diquark fragmentation into baryons are considered. It is shown that inclusive spectra of Δ resonances in the diquark fragmentation range in νp and ν-barp interactions provide a basis for determination, if the mechanisms of diquark fragmentation into mesons and baryons are similar or distinct, and give information on the quark-gluon structure of nonstrange diquarks