Speaker
Description
In a magnetic field, particles with low transverse momentum (typically a few hundred MeV) follow a helical trajectory that curls within the detector, leading to one or multiple ‘loops’ of the same particle. Particle ID detectors are typically situated at large radii above > 50 cm, and cannot provide measurements for low-pTtracks.
As the sensor technology for precision timing of single charged particles has advanced, most notably by the developments in silicon low-gain avalanche diodes (LGADs) to improve timing resolution, fill factor and signal sharing, the possibility of implementing time-of-flight -based particle ID layers at low radii comes within reach. The PID layer can be designed to recover the reconstruction performance of curling tracks and thereby extend the physics to lower kinematic regimes. The low material budget required as small radii can be pursued by reducing the inactive mass of large-area LGAD sensors, or the integration of a gain layer in a thin monolithic CMOS sensor process.
Here we present an analytical description for looping trajectories and their consecutive hits in a time-of-flight layer with 15-50 ps resolution, and a Geant4-based simulation study of the impact of various detector parameters on the PID performance. We investigate the potential of this detector concept at future collider experiments, with a focus on PID and event start time (T0) determination. We also present an early study of looping tracks in the EIC ePIC TOF detector, and introduce initial designs for a Fast Timing Layer in a Belle II detector upgrade.