The Performance of the Outer Tracker Detector at LHCb

The LHCb experiment is a single arm spectrometer, designed to study CP violation in $B$-decays at the Large Hadron Collider (LHC). It is crucial to accurately and efficiently detect the charged decay particles, in the high-density particle environment of the LHC. For this, the Outer Tracker was constructed, consisting of $\sim$55,000 straw tubes, covering in total an area of 360 m2 of double layers. A precise drift-time measurement results in a single hit resolution of 220 $\mu$m, at an average occupancy up to 10% and at 1 MHz trigger rate. At the time of the conference, the detector has been commissioned with almost two years of LHC beam collision data. After dedicated studies to establish timing and spatial alignment, the first results on the detector performance (efficiency, resolutions, etc.) have been obtained.