Abstract FR:

The subject of this thesis is the determination of the boson W mass in the fully hadronic channel within DELPHI experiment. Data are collected by the detector DELPHI during 1998 and 1999 with the (e)+(e)- LEP at CERN. W bosons collected were produced by pair in the process (e)+(e)- -> (W)+(W)- with a center of mass energy between 189 and 202 GeV. A significant part of work in the thesis was devoted to the pairing algorithm creation for the four jets and to the final mass determination of the W boson [. . . ]