Ageing of the LHCb outer tracker & $b$-hadron production and decay at $\sqrt{s}$=7 TeV

The Standard Model (SM) of particle physics describes all known elementary particles and their interactions. Despite its tremendous success, some problems remain not understood. The abundance of matter over anti-matter is still an open question. Also the nature of so- called dark matter, invisible matter that can only be detected through its gravitational force, is yet to be discovered. New Physics (NP) models have been proposed to answer these (and more) open questions. These models are usually extensions of the already existing SM that assume the existence of yet unknown particles and forces. The ATLAS and CMS experiments at the Large Hadron Collider (LHC) are designed to directly search for such new particles predicted by NP models. The LHCb experiment, however, is designed to measure observables for which there are SM predictions. New particles can modify these observables. Therefore, precision measurements can reveal hints of NP. The experimental apparatus forms an integral part in the search for NP. I contributed to the control of the Outer Tracker subdetector system and monitored its performance using dedicated scans. In addition, I measured in detail the relative b -hadron production rates. This is needed to measure any B 0 s or Λ 0 b branching fraction at the LHC . Many B 0 s branching fractions are precisely predicted in the SM, and can thus reveal signs of NP. In this thesis, I measured four world best branching fractions.