High-Luminosity LHC

High-Luminosity LHC
Name	High-Luminosity LHC
Location	CERN
Status	Upgraded phase
Operator	European Organization for Nuclear Research (CERN)

High-Luminosity LHC The High-Luminosity upgrade is a major enhancement to the Large Hadron Collider program at CERN designed to increase integrated luminosity for precision measurements and rare-process searches. The project involves international collaboration among institutions such as Fermi National Accelerator Laboratory, DESY, INFN, and KEK, and ties into broader particle physics initiatives like the Particle Physics Project Prioritization Panel and the European Strategy for Particle Physics.

Overview

The upgrade aims to augment the Large Hadron Collider complex operated by CERN by increasing instantaneous luminosity through new magnets, focusing optics, and upgraded injector and detector systems, building on discoveries such as the Higgs boson observed by ATLAS experiment and CMS experiment. The program is coordinated with partners including Fermilab, Brookhaven National Laboratory, CEA Saclay, SLAC National Accelerator Laboratory, and TRIUMF and is informed by advisory bodies like the European Strategy Group and the Particle Physics Project Prioritization Panel.

Physics Goals and Scientific Motivation

Primary goals include precision studies of the Higgs boson properties, searches for beyond-Standard-Model signatures predicted by frameworks such as Supersymmetry, Extra dimensions, and Dark matter models, and improved sensitivity to rare processes exemplified by Higgs to mu mu and Higgs self-coupling measurements. The upgrade supports long-term programs tied to experiments including ATLAS experiment, CMS experiment, LHCb experiment, and ALICE experiment and complements initiatives at facilities like International Linear Collider and Future Circular Collider design studies. Outcomes are expected to influence theoretical programs from groups associated with CERN Theory Division and collaborations with institutes such as Institute for Advanced Study and Perimeter Institute.

Accelerator Upgrades and Technical Design

Key accelerator upgrades comprise installation of new superconducting magnet technology including Nb3Sn quadrupoles, implementation of novel crab cavity systems similar to designs studied at KEK and SLAC National Accelerator Laboratory, replacement of beam screen and cryogenic components developed in partnership with CERN Cryogenics Group, and enhancements to the injector chain involving PS Booster, Proton Synchrotron, and Super Proton Synchrotron. The project integrates contributions from laboratories including INFN, CNRS, Max Planck Society, and Lawrence Berkeley National Laboratory and relies on engineering standards exemplified by European Committee for Standardization practices. The design addresses beam dynamics challenges observed in experiments like UA1 and UA2 and leverages simulations informed by codes from CERN Openlab and collaborations with NERSC and CERN IT.

Detector Upgrades and Experimental Challenges

Detector upgrades for ATLAS experiment and CMS experiment include higher-granularity tracking systems, radiation-hard silicon sensors developed in coordination with Micron Technology, STMicroelectronics, and Hamamatsu Photonics, upgraded trigger and data-acquisition systems leveraging technologies from ATLAS Collaboration and CMS Collaboration, and enhanced calorimetry and muon systems building on R&D performed at DESY and RAL. Experimental challenges encompass pileup mitigation strategies informed by experience from Tevatron detectors at Fermilab, precision alignment drawing on methods used by BaBar and Belle II experiments, and data-processing demands comparable to projects at Square Kilometre Array and Large Synoptic Survey Telescope development groups.

Project Timeline, Construction, and Commissioning

The schedule involves phased civil engineering and installation activities coordinated with CERN operations, overlapping with timelines from partner institutions such as Fermilab and INFN and governance by bodies like the CERN Council. Construction and component production have drawn on industrial partners in France, Germany, Italy, and United Kingdom and factory networks including ANSALDO Energia and Siemens. Commissioning phases will follow cold test campaigns and beam commissioning similar to procedures used during LHC startup and lessons learned from commissioning at RHIC and LEP.

Expected Performance and Physics Reach

With design targets aiming for an order-of-magnitude increase in integrated luminosity versus the baseline Large Hadron Collider datasets, the upgrade is expected to enable percent-level constraints on couplings of the Higgs boson measured by ATLAS experiment and CMS experiment, extended sensitivity to supersymmetric particles and vector-like quarks hypothesized in theories examined by groups at Institute for Theoretical Physics units, and improved measurements of rare decays explored by LHCb experiment and ALICE experiment. The enhanced dataset will inform global fits produced by collaborations with theorists from CERN Theory Division, Perimeter Institute, and Institut des Hautes Études Scientifiques and will shape future proposals like the Future Circular Collider and the International Linear Collider.

Category:Particle accelerators Category:CERN projects