Performance of CMS Muon Reconstruction in Cosmic-Ray Events

TL;DR

This paper evaluates the performance of CMS muon reconstruction using cosmic-ray data, demonstrating high efficiency, accurate momentum resolution, and low charge misassignment across a wide range of muon energies.

Contribution

It provides a comprehensive assessment of muon reconstruction performance in CMS using cosmic-ray data, validating simulation models and detector capabilities.

Findings

Muon reconstruction efficiencies are in good agreement with simulations.

Momentum resolution is better than 1% at 10 GeV/c and about 8% at 500 GeV/c.

Charge misassignment is below 1% at high energies.

Abstract

The performance of muon reconstruction in CMS is evaluated using a large data sample of cosmic-ray muons recorded in 2008. Efficiencies of various high-level trigger, identification, and reconstruction algorithms have been measured for a broad range of muon momenta, and were found to be in good agreement with expectations from Monte Carlo simulation. The relative momentum resolution for muons crossing the barrel part of the detector is better than 1% at 10 GeV/c and is about 8% at 500 GeV/c, the latter being only a factor of two worse than expected with ideal alignment conditions. Muon charge misassignment ranges from less than 0.01% at 10 GeV/c to about 1% at 500 GeV/c.