Mark Thomson, a professor of experimental particle physics at Cambridge, has been appointed as the next director general of CERN, the European nuclear research organization. His tenure begins on January 1st with a seemingly counterintuitive first move: shutting down the Large Hadron Collider (LHC), the world’s largest and most powerful particle accelerator. This shutdown isn’t a setback, however, but a carefully planned step toward a substantial upgrade that will redefine the future of high-energy physics.
The LHC’s Legacy and the Coming Hi-Lumi Upgrade
The LHC earned its place in history by confirming the existence of the Higgs boson, a fundamental particle that explains how matter acquires mass. Despite this triumph, the machine is due for major improvements. Starting in June, the LHC will undergo an extensive shutdown to make way for the High-Luminosity LHC (Hi-Lumi LHC), an upgrade designed to dramatically increase the rate of particle collisions.
The Hi-Lumi LHC will utilize more powerful superconducting magnets to compress proton beams, increasing the number of collisions tenfold. This means more data, sharper measurements, and a higher chance of spotting new, exotic particles. The upgrade isn’t just about raw power; the detectors themselves are being reinforced to capture subtle signals that could reshape our understanding of physics.
Beyond the Shutdown: The Future Circular Collider
Thomson’s five-year term will be dominated by preparing for the Hi-Lumi LHC, but his long-term challenge is even greater: planning CERN’s next major investment. The LHC is slated to reach the end of its operational life around 2041, and scientists are already debating its successor. The leading proposal is the Future Circular Collider (FCC), an ambitious project that would dwarf the LHC in scale.
The FCC would be over three times larger than the current collider, requiring a 91km tunnel bored up to 400 meters underground. The project is broken into phases, beginning with an electron-positron collider in the late 2040s, followed by a proton collider capable of smashing particles at seven times the energy of the LHC by the 2070s. The initial phase alone is estimated to cost £14 billion.
The Bigger Questions and Global Competition
The FCC’s potential discoveries are far from guaranteed. The project faces questions about its ability to address some of physics’ most pressing mysteries: the nature of dark matter and dark energy, the weakness of gravity, and the imbalance between matter and antimatter in the universe.
Moreover, CERN isn’t alone in the race for particle physics dominance. The US and China are developing their own advanced collider projects, challenging Europe’s historic leadership in the field. Maintaining CERN’s position will require not only technological innovation but also securing international funding and collaboration.
“We’ve not got to the point where we have stopped making discoveries and the FCC is the natural progression. Our goal is to understand the universe at its most fundamental level,” Thomson stated.
The future of particle physics hinges on bold investment and continued scientific ambition. CERN, under Thomson’s leadership, is preparing for a new era of discovery, even if it means temporarily silencing the world’s most powerful machine.
