RICH alignment at LHCb with collision data

Abstract: The LHCb experiment, currently operating at CERN, is designed for the precision measurement of CP violation and other rare phenomena in the decays of B hadrons. LHCb employs two RICH detectors to provide particle identification essential for this physics program. To reach design performance, the geometrical alignment of the RICH detectors should be established and calibrations made for the effects of the LHCb magnetic field. This paper describes the procedures developed towards this alignment and calibration using data from LHC collisions which began on 23 November 2009. [Copyright &y& Elsevier]