Recherche des bosons de Higgs neutres dans les états finals à quatre jets avec le détecteur DELPHI

The search for the Higgs bosons is one of the priorities of LEP200 at CERN. Indeed the Higgs mechanism which predicts the existence of scalar bosons whose mass is unknown, allows to generate masses to all standard and supersymmetric particles. We have searched for the Higgs bosons produced in the two channels at LEP200 $e^+ e^- \to Z^{0*} \to h^0 Z^0$ and $e^+ e^- \to Z^{0*} \to h^0 A^0$ We have focussed our studies on final states containing four jets. They represent the majority of the final states....