The Performance and Development of the Inner Detector Trigger Algorithms at ATLAS for LHC Run 2

TL;DR

This paper discusses the upgrade and performance of the inner detector trigger algorithms at ATLAS during LHC Run 2, highlighting design, optimization, and initial data results.

Contribution

It introduces a reimplementation of tracking algorithms with a profiling infrastructure for performance monitoring and presents their initial performance on LHC Run 2 data.

Findings

Trigger algorithms show improved performance after reimplementation.

Profiling infrastructure enables real-time performance feedback.

Initial data demonstrates effective trigger operation in Run 2.

Abstract

The upgrade to the ATLAS trigger for LHC Run 2 is presented including a description of the design and performance of the newly reimplemented tracking algorithms. The profiling infrastructure, constructed to provide prompt feedback from the optimisation procedure is described including the methods used to monitor the relative performance improvements as the code evolves. The performance of the trigger on the first data collected in the LHC Run 2 is presented.