Trigger and Analysis Strategies for $\Bs$ Oscillation Measurements in Hadronic Decay Channels

The capabilities of measuring $\Bs$ oscillations in proton-proton interactions with the ATLAS detector at the Large Hadron Collider are evaluated. $\Bs$ candidates in the $D_s^-\pi^+$ and $D_s^-a_1^+$ decay modes from semileptonic exclusive events are simulated and reconstructed using a detailed detector description and the ATLAS software chain. For the measurement of the oscillation frequency a $\Delta m_s$ sensitivity limit of 29.6~ps$^{-1}$ and a five standard deviation measurement limit of 20.5~ps$^{-1}$ are derived from unbinned maximum likelihood amplitude fits for an integrated luminosity of 10~\ifb\ . The initial flavour of the $\Bs$ meson is tagged exclusively with opposite-side leptons. Trigger strategies are proposed for scenarios of different instantaneous luminosities in order to maximise the signal channel trigger efficiencies.