On 22 April 2022, the Large Hadron Collider (LHC), the world’s largest and most powerful particle accelerator located on the outskirts of Geneva, restarted after a break of more than three years for maintenance and upgrade work.
One hope is that the LHC, a machine that smashes protons together, can find evidence of a fifth force of nature in addition to the known forces of gravity, electromagnetism and strong and weak nuclear forces.
After the upgrade, protons circulating in opposite directions around the LHC’s 27-kilometre ring will eventually be injected at a record energy of 13.6 trillion electronvolts (13.6 TeV).
A test on 22 April 2022 injected protons at an energy of 450 billion electronvolts (450 GeV). The energy will be ramped up between now and July 2022 to 6.8 trillion electronvolts (6.8 TeV) at which point the real physics will start again, marking the beginning of four years of experimentation.
“The machines and facilities underwent major upgrades during the second long shutdown of CERN’s accelerator complex,” says CERN’s Director for Accelerators and Technology, Mike Lamont. “The LHC itself has undergone an extensive consolidation programme and will now operate at an even higher energy and, thanks to major improvements in the injector complex, it will deliver significantly more data to the upgraded LHC experiments.”
In addition, ALICE, a specialised detector for studying heavy-ion collisions, can expect a fifty times increase in the total number of recorded ion collisions, thanks to the recent completion of a major upgrade.
The unprecedented number of collisions will allow international teams of physicists at CERN and across the world to study the Higgs boson in great detail and put the Standard Model of particle physics and its various extensions to the most stringent tests yet, wrote CERN.
The coming experiments are the best chance so far for finding new subatomic particles. The hope is these discoveries will spark the biggest revolution in physics in a hundred years.
As well as hoping to find a possible fifth force of nature, scientists hope to find evidence of Dark Matter, an invisible substance that makes up most of the universe.