Measurements of the Tau g-2 in Pb-Pb Collisions at the CMS Experiment and Future Improvements of the CMS Tracker

Although the Standard Model (SM) of particle physics has been remarkably successful, it still faces some theoretical and experimental challenges, including an up to 5.1 sigma deviation of the observed g-2 factor of muons compared to the SM prediction, hinting on beyond SM contributions. Such contributions are expected to be larger for tau leptons due to their higher mass, but the short lifetime of tau leptons prohibits a direct measurement of its g-2 factor. In this dissertation, the first measurement of the tau g-2 factor at the LHC and an improved measurement both using the recorded ultraperipheral collisions of Pb ions by the CMS experiment during Run2 of the LHC are presented. The prospects of this measurement for Run3 and the HL-LHC era are discussed, which motivate the upgrade of the CMS detector and particularly the tracking system, for which my contributions are detailed

Characterization of passive CMOS sensors with RD53A pixel modules

Both the current upgrades to accelerator-based HEP detectors (e.g. ATLAS, CMS) and also future projects (e.g. CEPC, FCC) feature large-area silicon-based tracking detectors. We are investigating the feasibility of using CMOS foundries to fabricate silicon radiation detectors, both for pixels and for large-area strip sensors. A successful proof of concept would open the market potential of CMOS foundries to the HEP community, which would be most beneficial in terms of availability, throughput and cost. In addition, the availability of multi-layer routing of signals will provide the freedom to optimize the sensor geometry and the performance, with biasing structures implemented in poly-silicon layers and MIM-capacitors allowing for AC coupling. A prototyping production of strip test structures and RD53A compatible pixel sensors was recently completed at LFoundry in a 150nm CMOS process. This presentation will focus on the characterization of pixel modules, studying the performance in terms of charge collection, position resolution and hit efficiency with measurements performed in the laboratory and with beam tests. We will report on the investigation of RD53A modules with 25x100 μm$^{2}$ cell geometry

Characterization of passive CMOS sensors with RD53A pixel modules

Both the current upgrades to accelerator-based HEP detectors (e.g. ATLAS, CMS) and also future projects (e.g. CEPC, FCC) feature large-area silicon-based tracking detectors. We are investigating the feasibility of using CMOS foundries to fabricate silicon radiation detectors, both for pixels and for large-area strip sensors. A successful proof of concept would open the market potential of CMOS foundries to the HEP community, which would be most beneficial in terms of availability, throughput and cost. In addition, the availability of multi-layer routing of signals will provide the freedom to optimize the sensor geometry and the performance, with biasing structures implemented in poly-silicon layers and MIM-capacitors allowing for AC coupling. A prototyping production of strip test structures and RD53A compatible pixel sensors was recently completed at LFoundry in a 150nm CMOS process. This presentation will focus on the characterization of pixel modules, studying the performance in terms of charge collection, position resolution and hit efficiency with measurements performed in the laboratory and with beam tests. We will report on the investigation of RD53A modules with 25x100 μm$^{2}$ cell geometry