Determination of underlying event contribution to the jet energies in CMS heavy ion collisions

The aim of nucleus-nucleus collisions at the ultra relativistic colliders is obtaining the hot and dense partonic matter. This partonic matter is required to study fundamental of quantum chromo dynamics (QCD). This hot and dense matter is reach the extremely high temperature and energies at the nuclei collisions. At the first moments of the nuclei collisions, the temperature of Quark gluon plasma and its density went down when the plasma going in to stable and during the this dense and temperature change is open the way of hadronization process for the QGP. There is two way to observe the properties of QGP, soft probes and hard probes. This thesis focused on the one of the hard probes; jets. The energy of jets, reconstruction of jet and background contribution to jet energy is studied and investigated well.