Validation of Kalman Filter alignment algorithm with cosmic-ray data using a CMS silicon strip tracker endcap

TL;DR

This paper validates a Kalman Filter alignment algorithm for a CMS silicon tracker endcap using cosmic-ray data, demonstrating good agreement with photogrammetry and hardware alignment methods.

Contribution

It introduces an experiment-independent implementation of the Kalman Filter alignment algorithm with outlier rejection and weak parameter treatment, applied to real detector data.

Findings

Good agreement with photogrammetry measurements

Consistent results with hardware alignment system

Effective outlier rejection in the alignment process

Abstract

A Kalman Filter alignment algorithm has been applied to cosmic-ray data. We discuss the alignment algorithm and an experiment-independent implementation including outlier rejection and treatment of weakly determined parameters. Using this implementation, the algorithm has been applied to data recorded with one CMS silicon tracker endcap. Results are compared to both photogrammetry measurements and data obtained from a dedicated hardware alignment system, and good agreement is observed.