Development of a Level 1 Track Trigger for the CMS experiment at the high-luminosity LHC

Over the next decade, several upgrades in the LHC and its injector chain will eventually increase the luminosity by up to a factor of 10 compared to the original design figure of 1034 cm−2 s−1. In order to cope with the large number of interactions per bunch crossing, a novel tracking system for the CMS experiment will be designed and built. The new tracker will also provide information to the Level 1 trigger decision, in order to improve the ability of selecting interesting physics channels in a higher density environment. The CMS collaboration is developing a novel module concept (“pT-module”), where signals from two closely spaced sensors are correlated in the front-end electronics, to select pairs of hits compatible with particle pT above a certain threshold. Selected pairs of hits, called “track stubs”, represent between 5% and 10% of the overall data rate: such a reduction factor enables the data processing at Level 1. Two main types of pT-modules are being developed, one based on strip sensors, and the other coupling a strip sensor with a pixelated sensor, which provides also precise information in the z coordinate. The main features of the pT-module options under development are reviewed, as well as the benchmark results from simulation studies.