The upgrade of the CMS pixel detector for LHC Phase 1

During the High-Luminosity upgrade of the LHC, the current CMS pixel detector will have to be replaced by a more efficient and radiation-hard device which is able to cope with the demands imposed by the improved performance of the accelerator. The goals of the upgrade project for the pixel detector are: replacement of the current system with four barrel layers and three endcap disks, to reduce dead time in the readout, to lower the material budget and to provide four-hit pixel coverage out to pseudorapidities of 2.4. With these design modifications, the upgraded pixel detector is expected to provide improved vertex reconstruction and tracking efficiencies, as well as better impact parameter resolution, with respect to the current 3 barrel layer and 2 endcap disk system. An overview of the envisaged design options for the upgraded CMS pixel detector is given, as well as estimates for the tracking and vertexing performance of the device. Furthermore, results from a simulation showing the improved impact parameter resolution and b-tagging capability are presented.