The Large Hadron Collider (LHC) has reopened for business, and this time it's more powerful than ever before. The LHC has been closed for two years while engineers did essential upgrades to nearly double its power. On May 21st, the results of the first proton collisions in the revamped machine were published.
The upgrade increased the machine's power from 8 Terra electronVolts (TeV) in 2012 to an eye-watering 13 TeV. This value determines the maximum speed of the particles zooming around the collider, and therefore what happens when they collide. With nearly double the power, the LHC will be able to produce newer, heavier particles than ever before.
The first collisions, such as the ones published today, are just the results of tests being run to make sure the LHC is ready for some epic physics. This includes aligning the orbits of the colliding protons, as well as refining and ensuring the beams' quality. This is a delicate process.
"When we start to bring the beams into collision at a new energy, they often miss each other," says Jorg Wenninger of the LHC Operations team. "The beams are tiny – only about 20 microns in diameter at 6.5 TeV; more than ten times smaller than at 450 GeV. So we have to scan around – adjusting the orbit of each beam until collision rates provided by the experiments tell us that they are colliding properly."
You can barely mention LHC without also including the buzz word: Higgs boson. The Higgs boson, the building-block particle that is responsible for giving particles mass, is really quite heavy, weighing around 125 GeV (Giga electronVolts). In order to see more of these particles (and other unknown, heavier particles) the LHC needs more energy.
There are plenty of other particles and discoveries that you might also want to watch out for. For example, supersymmetric particles: Every particle that exists at the moment is thought to have a supersymmetric partner. Spotting these would solve a lot of major particle problems, and they should be visible at high energies. We may even be able to find evidence of extra dimensions and recreate the plasma that was floating around just a moment after the Big Bang.
The journey to unlocking the secrets of the smallest components of particles continues now. Who knows what will emerge from these higher energies. Jon Butterworth, who works on ATLAS, hopes to see dark matter—a neutral, unobservable particle that accounts for the majority of mass in the universe.
For now, we wait with bated breath for the LHC to reveal some of the secrets of the universe.