The scientific potential and technological challenges of the High-Luminosity Large Hadron Collider program

Oliver Brüning; Heather Gray; Katja Klein; Mike Lamont; Meenakshi Narain; Richard Polifka; Lucio Rossi

doi:10.1088/1361-6633/ac5106

The scientific potential and technological challenges of the High-Luminosity Large Hadron Collider program

Rep Prog Phys. 2022 Mar 29;85(4). doi: 10.1088/1361-6633/ac5106.

Authors

Oliver Brüning¹, Heather Gray², Katja Klein³, Mike Lamont¹, Meenakshi Narain⁴, Richard Polifka⁵, Lucio Rossi⁶

Affiliations

¹ CERN, Geneva, Switzerland.
² UC Berkeley/LBNL, CA, 94720, United States of America.
³ RWTH Aachen University, 52074 Aachen, Germany.
⁴ Brown University, Providence, RI, 02906, United States of America.
⁵ CTU in Prague, Faculty of Nuclear Sciences and Physical Engineering, Brehova 7, 115 19 Praha 1, Czech Republic.
⁶ Physics Department of the University of Milano and INFN-Sezione di Milano, Laboratorio LASA, viale fratelli Cervi 201, 20056 Segrate (MI), Italy.

PMID: 35105832
DOI: 10.1088/1361-6633/ac5106

Abstract

We present an overview of the High-Luminosity (HL-LHC) program at the Large Hadron Collider (LHC), its scientific potential and technological challenges for both the accelerator and detectors. The HL-LHC program is expected to start circa 2027 and aims to increase the integrated luminosity delivered by the LHC by an order of magnitude at the collision energy of 14 TeV. This requires upgrades to the injector system, accelerator complex and luminosity levelling. The two experiments, ATLAS and CMS, require substantial upgrades to most of their systems in order to cope with the increased interaction rate, and much higher radiation levels than at the current LHC. We present selected examples based on novel ideas and technologies for applications at a hadron collider. Both experiments will replace their tracking systems. We describe the ATLAS pixel detector upgrade featuring novel tilted modules, and the CMS Outer Tracker upgrade with a new module design enabling use of tracks in the level-1 trigger system. CMS will also install state-of-the-art highly segmented calorimeter endcaps. Finally, we describe new picosecond precision timing detectors of both experiments. In addition, we discuss how the upgrades will enhance the physics performance of the experiments, and solve the computing challenges posed by the expected large data sets. The physics program of the HL-LHC is focused on precision measurements probing the limits of the Standard Model (SM) of particle physics and discovering new physics. We present a selection of studies that have been carried out to motivate the HL-LHC program. A central topic of exploration will be the characterization of the Higgs boson. The large HL-LHC data samples will extend the sensitivity of searches for new particles or new interactions whose existence has been hypothesized in order to explain shortcomings of the SM. Finally, we comment on the nature of large scientific collaborations.

Keywords: ATLAS; CMS; HL-LHC; Higgs boson; physics beyond standard model; upgrade.

Publication types

Review