Operation of the ATLAS Trigger System in Run 2

ATLAS COLL. , M. AABOUD, M.T. DOVA ET AL.; ATLAS COLL. , M. AABOUD, M.T. DOVA ET AL.

JOURNAL OF INSTRUMENTATION

IOP PUBLISHING LTD

Lugar: Londres; Año: 2020

1748-0221

The ATLAS experiment at the Large Hadron Collider employs a two-level trigger system torecord data at an average rate of 1 kHz from physics collisions, starting from an initial bunchcrossing rate of 40 MHz. During the LHC Run 2 (2015?2018), the ATLAS trigger systemoperated successfully with excellent performance and flexibility by adapting to the variousrun conditions encountered and has been vital for the ATLAS Run-2 physics programme.For proton?proton running, approximately 1500 individual event selections were includedin a trigger menu which specified the physics signatures and selection algorithms used forthe data-taking, and the allocated event rate and bandwidth. The trigger menu must reflectthe physics goals for a given data collection period, taking into account the instantaneousluminosity of the LHC and limitations from the ATLAS detector readout, online processingfarm, and offline storage. This document discusses the operation of the ATLAS trigger systemduring the nominal proton?proton data collection in Run 2 with examples of special data-takingruns. Aspects of software validation, evolution of the trigger selection algorithms duringRun 2, monitoring of the trigger system and data quality as well as trigger configuration arepresented.