Commissioning and Performance of the CMS Pixel Tracker with Cosmic Ray Muons

TL;DR

This paper reports on the commissioning and initial performance results of the CMS pixel tracker with cosmic ray muons, demonstrating that the detector meets design specifications and achieves an impact parameter resolution of 18 microns.

Contribution

It presents the first operational experience and performance measurements of the CMS pixel tracker installed in 2008 during cosmic ray data taking.

Findings

Impact parameter resolution of 18 microns for high momentum muons

Detector performance consistent with design specifications

Successful commissioning with charge injections

Abstract

The pixel detector of the Compact Muon Solenoid experiment consists of three barrel layers and two disks for each endcap. The detector was installed in summer 2008, commissioned with charge injections, and operated in the 3.8 T magnetic field during cosmic ray data taking. This paper reports on the first running experience and presents results on the pixel tracker performance, which are found to be in line with the design specifications of this detector. The transverse impact parameter resolution measured in a sample of high momentum muons is 18 microns.