Observation of the associated production of a J/psi meson with a W boson in pp collisions at 8 TeV using the ATLAS detector

Abstract: In this thesis the observation of the rare associated particle production of a J/psi meson in association with a W boson is reported using 20.3 fb^-1 of data from proton-proton collisions at 8 TeV with the ATLAS detector. Currently, the way a J/psi meson is produced at the Large Hadron Collider is not well understood and there are competing theories to describe this production. In combination with this analysis, the observation of a J/psi meson in association with a Z boson, which is expected to have a lower production rate, is also done. A preliminary observation of the Z boson is done to familiarise with the analysis process. The Z boson reconstruction from the data is also compared with Monte Carlo simulation. The observation of the particle productions are done using the dimuon decay channel for the Z boson and J/psi meson. The W boson is reconstructed from a muon and a neutrino using the events missing energy. A total of 171 event candidates from J/psi+W production and 13 from J/psi+Z production are reported.