Performance of the LHCb VELO

LHCb is a dedicated experiment to search for new physics in the decays of beauty and charm hadrons at the Large Hadron Collider (LHC) at CERN. Measurement of the flight distance of these hadrons is critical for the physics programme. The Vertex Locator (VELO) is a silicon micro-strip detector which surrounds the LHCb interaction point and provides μ m resolution of charged tracks and vertex positions. The VELO has been run successfully for the 2010 and 2011 LHC physics runs. Operational results show a signal-to-noise ratio of approximately 20 and a best hit resolution of 4 μ m .