Beam background effects in the CMS pixel detector

During the LHC run in December 2009 beam-induced background events were identified with the CMS pixel detector. The background consists mostly of collimated particle jets that traverse CMS parallel to the proton beam. The rate and origin of these events were studied, as well as the possible effects on the lifetime of the detector. In addition, a pixel-based method to remove the background for physics analyses was developed.