The world's largest science machine, the Large Hadron Collider (LHC), is facing a pivotal moment as it prepares for its third 'Long Shutdown' and an upgrade to the 'High Luminosity' LHC. This massive undertaking, costing roughly $1.5 billion, aims to increase the rate of collisions and the number of net collisions, offering greater odds of sighting exotic particles and signatures to the as yet unknown undercurrents that birthed our universe. However, the question remains: after the Higgs boson, what next?
The LHC has already made significant contributions to our understanding of the universe, including the discovery of the Higgs boson, which confirmed a theory that earned Peter Higgs and François Englert the Nobel Prize in physics in 2013. But the collider has also verified the Standard Model in fine detail, revealing that ordinary matter is built from quarks held together by the strong force, and filling in the family of hadrons, including exotic four- and five-quark species.
Despite these achievements, the LHC's upgrades and future plans are driven by the hope of discovering signs of dark energy and dark matter, which make up 95% of our universe. The Future Circular Collider (FCC), an electron–positron 'Higgs factory' in a 91-kilometre tunnel, has been endorsed by the CERN Council as its preferred project. However, not everyone is convinced, with some arguing that such a machine would primarily pin down quantities already known to a few more decimal places.
The challenge of funding and international collaboration is also a significant consideration. At CERN, Dr. Archana Sharma notes that 'for every penny there is a huge discussion' – and then consensus. The desire to contribute is more important than the geographic location, with India having worked at CERN since the 1960s. The question remains: will the FCC be built, and what will it reveal about the universe?
