Speaker
Description
The Large Hadron Collider (LHC) at CERN provides the world's highest
center-of-mass energy proton–proton collisions. The ATLAS detector, located at
one of the collision points, aims to discover phenomena beyond the Standard
Model by observing particles produced in these collisions. From 2030, the
High-Luminosity LHC (HL-LHC) will begin operation, increasing the instantaneous
luminosity by about a factor of three. In preparation for HL-LHC, we report on
studies of firmware optimization for the first-level muon trigger in the HL-LHC
ATLAS experiment. Real-time muon track detection is implemented around a
“Coincidence Window,” which projects hit combinations across three detector
stations into momentum space through a predefined mapping. This is realized
with RAM resources of FPGAs, where the input addresses correspond to hit
patterns and the output to the associated track parameters. In the endcap
region, the reconstruction principle is based on the point-angle measurement,
and the reconstructed tracks are expected to follow straight-line trajectories.
Non-straight combinations are rejected with null outputs, thereby serving as a
pattern-finding mechanism. Optimization is performed, respecting different
tasks for the three stations: while the first and third stations mainly
determine the momentum, the second station serves as a confirmation layer.
Relaxing the straight-line constraint in the second station within a controlled
range improves efficiency in the presence of multiple scattering and maintains
robust performance against detector misalignments. As a result, the platecu
efficiency for transverse momentum improves from 93.7% to 94.5%, and, in the
case of misalignments, from 85.9% to 93.5%. This optimization achieves a
significant performance gain without increasing FPGA resource usage or latency.
Moreover, it contributes to overall resource reduction and design
simplification of the trigger system. In this presentation, we present this study's
concept, motivation, optimization methodology, and performance improvements.
| Position | TBC |
|---|---|
| Affiliation | TBC |
| Country | TBC |