The LHC is back! What are your next experiences?

This Friday, April 22, 2022, near Geneva, 100 meters deep, the most powerful particle accelerator resumed its activities. At a speed of 450 billion electron volts (450 gigaelectron volts GeV), two proton beams traveled in opposite directions along the LHC (Large Hadron Collider) ring. ” These beams traveled with injection energy and contained a relatively small number of protons. High-intensity, high-energy collisions are expected in a few months said Rhodri Jones, head of the beam department at CERN, the European Organization for Nuclear Research, in a statement.

>>> Read also: Particle physics: neutron structure is more complex than expected

The shutdown was carried out with the aim of improving and increasing the power of the machines, and in particular that of the injectors and beams, in order to increase the number of collisions at the LHC, explains Rende Steerenberg, chief of operations on the beam. department in a video published by CERN. Upcoming tests will also check that all devices are working properly and at the same time, he adds.

What is the LHC?

The Large Hadron Collider officially began operations on September 10, 2008 and was built with the goal of colliding particles at the highest possible speeds, close to those of light, to generate infinitely small particles. . It consists of a 27-kilometer-long ring with tubes made of ultra-high vacuum superconducting magnets where the beams of particles flow in opposite directions.

After more than 3 years off, what are the next projects for the LHC?

1. Set a new energy record

Gradually, CERN teams will increase the intensity of the beams during this third period of the LHC, called “Run 3”. The goal? Achieve a record energy of 13.6 trillion electron volts (13.6 tetraelectron volts TeV), compared to the previous 8 TeV. This colossal energy will also allow detectors to reach a record number of collisions and thus collect more data. The LHCb detector will triple its number of collisions, while the collisions of the ALICE detector will multiply by fifty.

2. Study the Higgs boson in detail

In 2012, the LHC confirmed for the first time the existence of the Higgs boson, also known as the W boson, an elementary particle that explains why some particles have mass while others do not. Although it was a purely theoretical concept, its detection allowed scientists to think of a new physics that could postulate or explain supersymmetry or even dark matter.

With the resumption of LHC activities, CERN teams want to continue to deepen their knowledge of the Higgs boson using the LHCb detector (one of the four main LHC detectors). In fact, during previous experiments with this detector, the W boson ” it did not behave as expected as predicted by the standard model of particle physics, says physicist Harry Cliff.

Therefore, scientists hope to be able to observe the different decay channels of the W boson. The discrepancy between the observations and predictions of scientists would then be a sign of new physics, says Ursula Bassler, deputy scientific director of the National Institute of Nuclear Physics. . and particle physics from the CNRS.

3. Find a new type of force that can explain dark matter or supersymmetry

With the collapse of the standard model of particle physics, a new physics is emerging on the horizon. This could explain and explain new particles such as dark matter or supersymmetric particles.

Two new experiments, called FASER i [email protected] they were specifically designed to look for physics beyond the standard model. These experiments will consist especially of the realization proton-helium collisions and find how often antimatter protons occur »Details the CERN press release. Again, the collisions of oxygen ions will allow us to observe in more detail the physics of cosmic rays and quark-gluon plasma. The latter is a set of particles that reigned after the Big Bang and could help us better understand why there is more matter than antimatter in the universe.

So far, dark matter has been deduced by observing galaxies but remains undetectable. Constituting more than a quarter of the energy of the Universe, it remains one of the greatest mysteries of physics. By conducting collision experiments with the LHC, dark matter particles could easily disappear, but by making an energy balance, scientists will be able to witness a deficiency and attribute it to dark matter.

In addition, supersymmetry could explain the value of the mass discovered by the Higgs boson. ” This value is very disturbing because it puts the vacuum in an unstable situation, as if the whole Universe is in danger of disintegrating at any moment! »explains Yves Sirois, head of the CMS experience for France at the CNRS site. Therefore, supersymmetry would be an explanation of the stability of the vacuum as we observe it.

“It simply came to our notice then announces physicist Harry Cliff of Cambridge University. Finding traces of extra-spatial dimensions or other types of Higgs boson … the possibilities are endless. It is not just the 12,000 CERN scientists working on the particle accelerator who are carefully setting this expectation, but the rest of the scientific community, experts and amateurs alike.

>>> Read also: LHC anomaly: meson b disintegrates strangely

Originally published on 04/26/2022

Leave a Comment