ATLAS trigger menu and performance in Run 1 and prospects for Run 2

Abstract

The ATLAS trigger system plays a key role in the collection of data for a wide range of physics analyses. The 2012 proton run had significantly larger luminosities and pile-up than the 2011 run. To address these challenges while maintaining or even improving performance, new algorithms have been commissioned. The trigger strategy and the main algorithms and their performance are described. For the 2015 run, the combination of a luminosity increase and an energy increase will put even larger demands on the trigger system. We describe here modifications to the trigger system to address these demands both at the hardware and software levels.