In this document, ten years of activities in the BaBar experiment, as well as my research project in the AMS experiment, are presented. We describe the experimental setup related to BaBar and the main results obtained by this experiment. My research in BaBar is focused on the study of the B -> Dbar() D() K final states. There are 22 final states which present very interesting properties. First of all, they constitute a non negligible fraction of the B meson decays and a measurement of the branching fractions is presented. This measurement allows to study the isospin relationships between all the final states. These decays give also insights on the angles of the unitary triangle related to the CP violation. The B -> Dbar() D() K events contain many resonances, and some of them are still poorly known and remain mysterious. We describe a study performed on resonances such as the X(3872) or Ds1*(2700), using either invariant mass distributions or Dalitz plot analysis. Finally, my research project on AMS is presented, and we explain the interest of measuring the positron fraction as well as the positron spectrum. Discrepancies with respect to the predictions could be the sign of nearby pulsars, or could constitute also the indirect observation of dark matter annihilation.
