Here’s what to know about the world’s largest and most powerful particle accelerator, which will be fully restarted on Tuesday

It is poised to revolutionize our knowledge of the universe once again. CERN’s Large Hadron Collider (LHC) is set to reach full power on Tuesday 5 July. After a three-year shutdown for maintenance and development work, it resumed operations on April 22. Franceinfo hosts the world’s largest particle accelerator, a tiny temple of infinite exploration.

It is 27 km long and 100 meters underground

The LHC is a ring with a diameter of 27 km, buried 100 m underground, on the border of France and Switzerland, not far from Geneva. If the device is buried deep, it “To avoid contamination by cosmic particles that could interfere with experiments”, as Cern explains in this video presentation of the LHCb experiment. Access to the particle accelerator is very secure: a device scans the viewer’s iris before taking the elevator that connects it to the surface.

Why do we need such large instruments to study the infinitesimally small? In short, Tell me in detail Atomic Energy and Alternative Energy Commission (ECA), particles behave like waves or waves. According to quantum mechanics, energy is inversely proportional to wavelength. That’s why working with shorter wavelengths requires a much larger amount of energy.

It is the scene of (very) violent conflicts

The LHC is a collider. Inside, physicists drive protons, particles located in the nucleus of atoms. In the ring, two beams of protons each spin in one direction. They move near the speed of light and collide and explode. The more violent these collisions are, the more they break up particles, helping scientists identify their constituents and their interactions.

After three years of operation, the LHC will reach its full collision power of 13.6 billion electron volts (TeV). This is unprecedented, notes Laurent Vegavant, deputy science director of the National Institute of Nuclear and Particle Physics. But what does it correspond to? “It’s very difficult to create because these are actually specific energy units in our field. They are infinite energies.”He agrees. “To give an idea, we compare this energy to the energy we often have to expend to fly a mosquito. Besides, at the LHC, this energy is concentrated in an intense way in the collision of two protons.”He says.

“Because protons are infinitesimally small, this creates an absolutely gigantic energy concentration.”Laurent GalliAt franceinfo

With this unprecedented power, physicists hope to get even more “Interesting Conflicts” And “Rare Events” Laurent Vacavant is concerned with the possible creation of new or previously unobserved particles.

The detectors of several experiments (ATLAS, CMS, ALICE and LHCb) distributed over the 27 km area of ​​the ring will then be responsible for capturing and recording the collisions. CMS, for example, acts as a giant camera that takes three-dimensional images of collisions. “We are aiming for a rate of 1.6 billion proton-proton collisions per second for the ATLAS and CMS experiments.”said Mike Lamont, Director of Accelerators and Technology at CERN.

It has already revolutionized physics

Thanks to the LHC, in 2012 Fabiola Gianotti, coordinator of the CMS experiment, announced the discovery of the Higgs boson. It revolutionized physics, confirming the prediction of researchers who, almost 50 years ago, were central to the Standard Model of particle physics (SM).

>> Seven Questions About Higgs Boson

“The Higgs boson is linked to some of the deepest questions in fundamental physics, from the structure and shape of the universe to how other particles organize themselves.”who is now Director General of CERN explained.

But the Higgs boson remains a mystery. “It is a base or a compound particle”That means a conglomeration of many yet unknown particles, wonders Joachim Minnich, Director of Research and Computation at CERN. “Is this the only Higgs particle that exists, or are there others?” He continues.

This will help us learn more about dark matter

“Finding the Higgs boson is like finding a needle in a haystack”, notes Laurent Vacavant. It took about 1.2 billion proton collisions to figure it out. The new LHC operating mode makes it possible to multiply this number by a factor of twenty. “Significant increases that pave the way for new discoveries”Judge Mike Lamont.

In addition to the Higgs boson, experiments at the LHC have already discovered more than 60 composite particles predicted by the Standard Model. With this new phase of the particle accelerator’s operation, scientists expect new discoveries. Laurent Vacavant specifically mentions dark matter. This phantom, mysterious matter is composed of exotic high-mass particles. According to some hypotheses, there may be five to seven times as much dark matter as visible matter in the universe. This means that matter as we know it (made up of atoms) makes up less than 20% of all the matter that makes up our universe.

This hitherto undetected and unobserved dark matter is a major key to understanding the motions of large structures such as galaxies and galaxies. Getting it out would be a major discovery, and tracking it down is a priority for researchers everywhere. “We know that dark matter is a particle that practically does not interactLaurent exposes Vacavant. Some specimens have a particle [hypothétique] called neutralino. As its name suggests, it is a very neutral particle that is hard to see. Depending on the mass of this neutralino, it could have all the properties of dark matter.”, he explains. The coming years at the LHC promise to be exciting.