First Tracking Performance Results from the ATLAS Fast TracKer (FTK)

Particle physicists at the Large Hadron Collider (LHC) investigate the properties of matter at length scales one million times smaller than the atom by colliding together high-energy protons 40 million times per second and observing the decay products of the collisions. ATLAS is one of two general-purpose detectors that reconstruct the interactions and as part of a wide range of physics goals measures production of Higgs bosons and searches for exotic new phenomena including supersymmetry, extra dimension and dark matter. Selecting the interesting collision events using hardware- and software-based triggers is a major challenge as reconstructing these collisions will only become more challenging as the LHC luminosity increases in future data. The ATLAS Fast TracKer (FTK) is a custom electronics system that performs fast FPGA-based tracking of charged particles for use in trigger decisions. In 2018, an FTK "Slice" covering a portion of the ATLAS detector was installed and commissioned using proton-proton collisions. This presentation will review the track-finding and track-fitting strategies employed by the FTK hardware and present the first tracking performance results for the FTK Slice in 2018 pp collisions data, including hit- and track-finding efficiencies, track parameter resolutions, and track purities.