Fragmentation of CDF jets: perturbative or non-perturbative?

Presented are the most recent jet fragmentation results from CDF: inclusive distributions of charged particle momenta and their kT in jets; average track multiplicities, as well as angular distributions of multiplicity flow, for a wide range of jet energies with ET from 40 to 300 GeV. The results are compared with Monte-Carlo and, when possible, analytical calculations performed in resummed perturbative QCD approximations (MLLA).