We consider the azimuthal and PT-dependence of hadrons produced in unpolarized Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes, within the factorized QCD parton model. It is shown that at small PT values, PT ≲ 1GeV/c, lowest-order contributions, coupled to unintegrated (transverse-momentum-dependent) quark distribution and fragmentation functions, describe all data. At larger PT values, PT ≳ 1GeV/c, the usual pQCD higher-order collinear contributions dominate. Having explained the full PT range of available data, we give new detailed predictions concerning the azimuthal and PT-dependence of hadrons which could be measured in ongoing or planned experiments by HERMES, COMPASS and JLab Collaborations.
13.88.+e Polarization in interactions and scattering 13.60.-r Photon and charged-lepton interactions with hadrons 13.85.Ni Inclusive production with identified hadrons