Performance of Resistive Plate Chambers installed during the first long shutdown of the CMS experiment

TL;DR

This paper reports on the installation, commissioning, and performance evaluation of 144 new Resistive Plate Chambers in the CMS muon system during LHC's first long shutdown, enhancing muon trigger efficiency.

Contribution

It presents the successful installation, commissioning, and performance analysis of new RPCs in the CMS muon system during LHC's first long shutdown.

Findings

RPCs were successfully installed and commissioned.

The new chambers improved muon trigger efficiency.

System operated successfully during data collection.

Abstract

The CMS experiment, located at the CERN Large Hadron Collider, has a redundant muon system composed by three different detector technologies: Cathode Strip Chambers (in the forward regions), Drift Tubes (in the central region) and Resistive Plate Chambers (both its central and forward regions). All three are used for muon reconstruction and triggering. During the first long shutdown (LS1) of the LHC (2013-2014) the CMS muon system has been upgraded with 144 newly installed RPCs on the forth forward stations. The new chambers ensure and enhance the muon trigger efficiency in the high luminosity conditions of the LHC Run2. The chambers have been successfully installed and commissioned. The system has been run successfully and experimental data has been collected and analyzed. The performance results of the newly installed RPCs will be presented.