This website has been developed and is being maintained on behalf of ESFRI by the StR-ESFRI project which has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement n° 654213
An upgrade of the highest-energy particle collider in the world to explore new physics
The Large Hadron Collider (LHC) at CERN is the highest-energy particle collider in the world. The LHC experiments (ALICE, ATLAS, CMS and LHCb) have produced a large number of beautiful physics results, summarised in more than 2.000 publications in peer-reviewed scientific journals as of today. The highlight is the breakthrough discovery of the Higgs boson by the ATLAS and CMS experiments in 2012. This discovery marked the start of a major programme to measure this particle’s properties with the highest possible precision with a view to testing the validity of the Standard Model and searching for new physics at the energy frontier. To extend its discovery potential, the LHC will be upgraded to the High-Luminosity LHC (HL-LHC).
The HL-LHC will be implemented over the coming decade in order to increase the data sample for ATLAS and CMS by an order of magnitude compared to the integral collected by the end of 2023. To benefit fully from the increased data sample in terms of scientific production, the LHC detectors will also need to be upgraded, together with the computing infrastructure required to handle the substantially increased data rates. The full exploitation of the LHC, including the HL-LHC, was identified as the highest priority for European particle physics, in the update of the European Strategy for Particle Physics approved by the CERN Council in May 2013. The HL-LHC project is considered a high-priority component also in the national roadmaps of many countries across the world, including the USA.
The accelerator and detector systems for the HL-LHC project will take close to a decade to complete. The accelerator relies on a number of innovative technologies including a combination of cutting-edge superconducting magnets, ultra-precise superconducting radiofrequency cavities for beam rotation, as well as high-power superconducting links with zero energy dissipation. In addition, the higher luminosity sets novel constraints on vacuum, cryogenics and machine protection, and will require new concepts for beam collimation and diagnostics to maximise the physics output of the collisions. The success of experiments at the HL-LHC will rely upon innovative instrumentation such as radiation-hard detectors, high-granularity calorimeters, and large-area silicon trackers, together with state-of-the-art infrastructures and large-scale data-intensive computing.
The first physics goal is to push further the validation of the Standard Model at the energy frontier, in particular by measuring, with the highest possible precision, the properties of the Higgs particle and the longitudinal components of the massive vector bosons, with a view to identifying any deviations from the Standard Model predictions. The second goal is to check whether the Higgs particle is accompanied by other new particles at the TeV energy scale, which could play a role in addressing outstanding questions in particle physics, such as the nature of dark matter and the matter-antimatter asymmetry in the Universe.
The LHC is a unique international infrastructure dedicated to studying the fundamental constituents of matter and their interactions. The high luminosity upgrade of the existing LHC will allow full exploitation of its scientific potential and will map out the scientific programme up to 2035 and possibly beyond. The scientific community at CERN consists of over 13 000 users from around the world, of whom a large majority work on the LHC.
The HL-LHC and its associated facilities will require a constant stream of supplies and services, including civil engineering and the systems and equipment needed to build and operate the accelerator and the experiments. Collaboration with many types of industries and businesses will be required in order to pursue the physics goals of the HL-LHC. Society will benefit greatly from the knowledge and technology that will be developed during the HL-LHC project. Many young physicists and engineers trained during the project will transfer their expertise to society and industry. Whether in the field of accelerators, detectors or computing, the HL-LHC is a major undertaking that will impact many technologies that are of relevance for other Research Infrastructures and for the Big Data and computing paradigm.