Looking for new physics in the $B_s^0 \rightarrow J/\psi \phi$ decay

The CP violating phase $\phi_s$ is measured in decays of $B^0_{s}\rightarrow J/\psi \phi$. This measurement uses 4.9 fb$^{-1}$ of data from the ATLAS detector at the LHC at CERN. This data consists of the 2011 run of $pp$ collisions at $\sqrt{s} = 7$ TeV. This measurement provides a means of potentially falsifying the standard model, which is known to provide insufficient levels of CP violation to account for the observable universe. This thesis includes material that has been publicly available in papers and ATLAS CONF notes, but provides greater detail. The measurement uses the proper decay time and angular distributions of the decay to measure key theoretical parameters of the flavour physics involved. The measurements in this thesis complement and compete with the measurements taken by various experiments around the world. This thesis contains details for both flavour tagged and untagged measurements. The tagged results are: $\phi_s = 0.12 \pm 0.25$ (stat.) $\pm 0.11$ (syst.) rad, $\Delta\Gamma_s = 0.053 \pm 0.021 $ (stat.) $\pm 0.009$ (syst.) ps$^{-1}$ , $\Gamma_s = 0.677 \pm 0.007$ (stats.) $\pm 0.003$ (sys.) ps$^{-1}$ ,