Speaker
Hale Sert
(RWTH Aachen University)
Description
The CMS experiment selects events with a two-level trigger system, the Level-1 (L1) trigger and the High Level trigger (HLT). The HLT is a farm of approximately 30K CPU cores that reduces the rate from 100 kHz to about 1 kHz. The HLT has access to the full detector readout and runs a streamlined version of the offline event reconstruction. In Run 2 the peak instantaneous luminosity reached values above $2 \times 10^{34}$ cm$^{-2}$ sec$^{-1}$, posing a challenge to the online event selection. An overview of the object reconstruction and trigger selections used in the 2016-2018 data-taking period will be presented. The performance of the main trigger paths and the lessons learned will be summarized, also in view of the coming Run 3.
Primary author
Hale Sert
(RWTH Aachen University)
