The authors have studied the W + ≥ n jets process in Tevatron Run II experiment. This is the first result for the CDF Run II experiment. The data used corresponds to a total integrated luminosity of 72 pb−1 taken from March 2002 through January 2003. The lowest order QCD predictions have been tested with a new prescription of the parton-jet matching, which allows to construct the enhanced LO phase space. They found a good agreement between data and theory in the typical kinematics distributions. Number of events for each inclusive samples up to 3 jets are compared with Monte Carlo calculations. The comparison with Run I results is also presented.

The authors have studied the W + {ge} n jets process in Tevatron Run II experiment. This is the first result for the CDF Run II experiment. The data used corresponds to a total integrated luminosity of 72 pb{sup -1} taken from Mar. 2002 through Jan. 2003. The lowest order QCD predictions have been tested with a new prescription of the parton-jet matching, which allows to construct the enhanced LO phase space. They found a good agreement between data and theory in the typical kinematics distributions. Number of events for each inclusive samples up to 3 jets are compared with Monte Carlo calculations. The comparison with Run I results is also presented.

In this thesis we present the study of the production of the W boson in association with hadronic jets at the Collider Detector at Fermilab (CDF). Along with the electroweak properties the W boson, we examine jet kinematic variables with the aim of studying predictions of perturbative quantum chromodynamics. We derive several di erential crosssections as a function of the inclusive jet multiplicity and the transverse momenta of each jet. In this analysis, we are using 2.8 fb-1 of data and consider both the electron and muon lepton nal states for the W boson decay.