We analyze inclusive jet and dijet production in positron(electron)–proton collisions at HERA energies. Using UPDFs with the KaTie parton-level event generator and DUPDFs through direct evaluation, we examine different ordering constraints and virtuality choices across the KMR and MRW approaches. The $(z, k_t)$-factorization framework is found to give better agreement with ZEUS data, particularly at high $Q^2$. We also study Z boson production in proton–proton collisions at $\sqrt{s}= 13$ TeV within the $k_t$ and $(z, k_t)$-factorization frameworks using MRW parton distributions. By including subprocesses up to next-to-leading order and according for final-state leptons, we extend earlier analyses. Comparisons with ATLAS, CMS, and LHCb data show that while both approaches perform similarly at central rapidities, the $(z, k_t)$-factorization framework provides closer agreement with data at forward rapidities. In both cases, differential cross sections are obtained with the KaTie parton-level event generator for $k_t$-factorization, while for $(z, k_t)$-factorization they are computed directly.

Together, these studies highlight the importance of DUPDFs, which preserve full parton kinematics and improve predictions across different processes and energy scales. They provide a consistent framework for describing both electroweak boson production at the LHC and jet observables at HERA.