When and where Precision time measurements with hybrid silicon pixel detectors

The future High Luminosity Large Hadron Collider at CERN, which is planned to start operations in early 2029, will see a substantially higher rate of collisions than the current Large Hadron Collider. This will allow for a faster collection of experimental data to increase the potential for new discoveries. However, the increased rate of collisions also poses a challenge for the reconstruction of collision events.
Silicon pixel detectors are used to measure the positions of decay products with high resolution at various points along their trajectories. From these measurements their tracks can be reconstructed and traced back to the collision point where they were produced. As the data rate is increased, the spatial separation between collisions decreases, making the spatial resolution insufficient to distinguish between different events. However, the collisions are also separated in time, and complementing the spatial information with time measurements—a method referred to as 4D tracking—may offer a solution.
The challenging simultaneous high-precision measurement of time and position with hybrid silicon pixel detectors is the main subject of this thesis. The presented research has aimed to assess the current state of time measurements with hybrid silicon pixel detectors; to identify the factors currently limiting the time resolution that can be achieved; and to develop an understanding of the challenges that lay ahead in the shift towards 4D tracking.