CMS track reconstruction performance during Run 2 and developments for Run 3

TL;DR

This paper reviews CMS's charged-particle track reconstruction performance during Run 2, highlighting upgrades made for high pileup conditions and ongoing developments for improved performance in Run 3, especially for the high-level trigger.

Contribution

It provides an overview of the iterative track reconstruction algorithms used in CMS during Run 2 and discusses ongoing improvements for Run 3, including high-level trigger enhancements.

Findings

Track reconstruction performance measured with simulated and collision data.

Upgrades to algorithms to handle high pileup in Run 2.

Ongoing developments to improve Run 3 performance, especially for the trigger.

Abstract

An efficient and precise reconstruction of charged-particle tracks is crucial for the overall performance of the CMS experiment. During Run 2 of LHC, significant upgrades were made to the track reconstruction algorithms in order to accommodate for the high pileup environment and the installation of an upgraded pixel detector in 2017. This paper provides an overview of the iterative track reconstruction algorithm used in CMS during Run 2 and of the performance measured both with simulated and collision data. Developments are ongoing to further improve track reconstruction in Run 3, especially for what concerns the CMS high-level trigger, and the status of these improvements will be discussed.