CMS Luminosity Based on Pixel Cluster Counting - Summer 2013 Update

The measurement of the LHC luminosity delivered to CMS in the 2012 proton-proton physics run is presented. Results are based on cluster counting from the silicon pixel detector. The luminosity calibration is updated using the Van der Meer scans performed in November 2012. The overall uncertainty on the integrated luminosity is estimated to be $2.5\% ~(\mathrm{syst.})+0.5\% ~(\mathrm{stat.})$.