Speaker
Description
The HL-LHC era will offer a rich physics program for the ATLAS experiment, alongside a significant challenge for detector performance given the increased pile-up levels of up to 140–200 simultaneous interactions per bunch crossing. The physics program requires a luminosity measurement precision of 1%, which ATLAS will meet using multiple complementary luminosity detectors spanning the full range of beam conditions, from the low-pileup van-der-Meer calibration regime to high-luminosity physics running. A key contributor to this effort is the High-Granularity Timing Detector (HGTD), built on novel Low-Gain Avalanche Detector (LGAD) silicon technology to achieve high timing resolution on tracks. In addition to supporting the Inner Tracker in the forward region and mitigating pile-up, HGTD will also provide luminosity measurement. This contribution presents an overview of ATLAS luminosity determination at the HL-LHC, along with recent developments and the current project status of HGTD as a luminosity detector.