CMS Upgrades for the High-Luminosity LHC Era

TL;DR

The CMS experiment is undergoing a comprehensive Phase-2 upgrade to enhance detector performance and data handling capabilities, enabling it to operate effectively in the high-luminosity environment of the HL-LHC starting in 2029.

Contribution

This paper details the extensive upgrade plans for CMS detectors, including new components and systems designed to handle increased collision rates and radiation levels.

Findings

Successful design of upgraded detector components

Enhanced data acquisition system readiness

Projected performance improvements under HL-LHC conditions

Abstract

The High-Luminosity LHC (HL-LHC) era, set to begin in 2029, will provide the general-purpose experiments with an instantaneous luminosity of up to $\mathcal{L} = 7.5 \times 10^{34}$ cm$^{-2}$ s$^{-1}$ from pp collisions at a centre-of-mass energy of 14 TeV. To fully exploit this unprecedented data set, the experimental setups must be upgraded to withstand the challenging conditions of the HL-LHC, including up to 200 simultaneous collisions per bunch crossing and a substantial radiation dose delivered to the detectors. The CMS collaboration is currently undertaking the Phase-2 upgrade, which aims to enhance the detector's capabilities to maintain high performance under these conditions. This upgrade includes significant improvements to the muon spectrometer and barrel calorimeter, a complete replacement of the silicon tracker, endcap calorimeter and beam radiation and luminosity subsystems, the introduction of a new MIP timing detector layer, and a redesigned trigger and data acquisition system. These enhancements will ensure that the CMS experiment can fully profit from on the HL-LHC data, maximising its physics potential and expanding its ability to make the most precise measurements.