Calibration of the CMS Drift Tube Chambers and Measurement of the Drift Velocity with Cosmic Rays

TL;DR

This paper details the calibration process for CMS drift tube chambers using cosmic ray data, focusing on determining drift velocities and timing corrections to improve muon detection accuracy.

Contribution

It introduces a calibration method for CMS drift tubes and refines drift velocity measurement accounting for cosmic ray timing variations.

Findings

Calibration achieves precise timing alignment for drift tubes

Drift velocity measurements are improved with offline analysis

Enhanced muon detection accuracy in CMS system

Abstract

This paper describes the calibration procedure for the drift tubes of the CMS barrel muon system and reports the main results obtained with data collected during a high statistics cosmic ray data-taking period. The main goal of the calibration is to determine, for each drift cell, the minimum time delay for signals relative to the trigger, accounting for the drift velocity within the cell. The accuracy of the calibration procedure is influenced by the random arrival time of the cosmic muons relative to the LHC clock cycle. A more refined analysis of the drift velocity was performed during the offline reconstruction phase, which takes into account this feature of cosmic ray events.