CMS Technical Design Report for the Pixel Detector Upgrade

The original design goal of the LHC was to operate at $1 \times 10^{34}$ cm$^{−2}s^{−1}$ with 25 ns bunch spacing, where approximately 25 simultaneous inelastic collisions per crossing (“pile-up”) occur. With the upgrade of the accelerators, the lumi- nosity and pile-up will more than double. The current pixel detector is crucial to charged particle tracking, but was not designed to perform effectively in such collision conditions and the physics program of CMS would suffer as a result. We propose to replace the current pixel tracker with a new high efficiency and low mass detector with four barrel layers and three forward/backward disks to provide four-hit pixel coverage out to pseudorapidities of ±2.5. This new detector will meet or exceed the original design specifications in these high luminosity environments. In this report, we provide details on the design, construction and installation of the upgraded pixel detector as well as estimates of its expected performance.