Performance studies of tracking-based triggering using a fast emulation

Experiments at the High-Luminosity phase of the LHC will face an increased number of interactions per bunch crossing. Several strategies have been evaluated by the ATLAS experiment to improve its trigger strategy in this context. One of the limitations in recovering events with low energy particles is the input rate of the Event Filter which necessitates high thresholds of Level-0 trigger items. As such, the potential use of tracking information prior to the Event Filter could particularly benefit to hadronic and di-lepton signatures. However, traditional track reconstruction techniques are known to be consumptive in terms of time and computational resources. A hardware fast-tracker solution, called L1Track, has been conceived to compute coarse-resolution tracks prior to the Event-Filter step. In this note we introduce a fast emulation of this system, allowing to explore various inputs to the tracking algorithm given the detector readout limits. The performance of simplified trigger algorithms on emulated L1Track tracks are investigated, highlighting the feedback that the emulation enables on the physics potential of a low latency hardware based track trigger.