The world’s largest research facility will soon be back in top form. The gigantic particle accelerator at the European Organization for Nuclear Research (CERN) in Geneva will be restarted from the end of March 2022 after a three-year maintenance break.

From June, proton beams will again be chased against each other at practically the speed of light in the 27-kilometer underground ring in order to generate collisions. Physicists hope for groundbreaking new findings, as Research Director Joachim Mnich of the German Press Agency says.

The particle accelerator, completed in 2008, simulates the time shortly after the Big Bang, i.e. the birth of the universe around 14 billion years ago. The researchers search for the fundamental laws of the universe and investigate the smallest components of matter, the elementary particles. For this purpose, particles are brought to collision in order to observe the resulting decay processes. Among other particles, it was possible in 2012 at Cern for the first time to detect the Higgs boson particle, theoretically described more than 40 years earlier, and the other elementary with its mass. It was considered the final piece of the puzzle in the Standard Model of particle physics.

Improved performance

In the course of the inventory, the performance of the accelerator and the connected detectors have been significantly improved. The number of high collisions should be twice as high as before. “We get access to processes that are very rare. The higher the number of collisions, the more precise the results,” says Mnich.

In the near future, particularly interesting findings can be expected in two fields, explains Mnich, who, prior to his appointment at the beginning of the year, was director for the field of particle and astroparticle physics at the German Electron Synchrotron (Desy) for a long time.

In one of the research facilities, the LHCb, observations were made for the first time this year, dying deviating from the standard model of physics, which describes twelve matter particles and their interaction. The so-called beauty quarks did not decay into muons and electrons in equal parts, as expected. The cause of the effect could be a previously unknown force of nature, says Mnich. However, the observation must be made significantly more often in order to have security.

“We hope that in the next two years we can clarify the question of whether this is real or a statistical mirage, describing all phenomena.”

“Elena” decelerator upgraded

A new age is also beginning for antimatter experiments, says Mnich, “perhaps with surprises”. The “Elena” decelerator (Extra Low ENergy Antiproton ring), which went into operation in 2017, has been upgraded during the maintenance phase. In it, the anti-protons are slowed down so that they can be better captured and observed. “We are looking at the question: Does antimatter fall down like normal matter or does it fall up?”, Says Mnich. Gravitation is a very weak force at the level of the sub-atoms, so it is very time-consuming to prove it.

What does all this bring for people? “Of course it is always a gain in knowledge. We try to understand what holds the world together, how nature works,” says Mnich. Particle research has also brought a lot of benefits. “It wasn’t clear at the time that the cell phone would develop from the discovery of how atoms work 100 years ago.” Among other things, the devices and processes developed at Cern are used in medicine, especially in cancer therapy and combating tumors. Not to be forgotten is the Internet, for which the then Cern computer specialist Tim Berners-Lee created the basis with the World Wide Web in 1990.

Ambitious plans

Cern has big plans: A leap for the particle accelerator will come in the second half of the decade, IF thanks to further expansions the so-called HiLumi phase begins: Then it will produce five to ten times more proton collisions per second than today and thus generate even more Data that scientists can evaluate. Until then, even stronger magnets are developed, the proton beams die at the collision points focus even more strongly. “There are already prototypes, but not all quality criteria have been met,” says Mnich.

The concept for an even larger accelerator is on the table for the 1940s: a ring that is 100 kilometers instead of the previous 27 kilometers. The feasibility studies for this have been running since summer. With its current particle accelerator, it is a world leader, but in Japan and especially in China.

The next champagne bottles will now be chilled at Cern for June 2022. Then two months of the careful start-up should be completed. “It’s not like a car: turn the key and off you go,” says Mnich. The smallest mistakes could destroy devices worth millions. When the first collisions occur in June, this can be seen on the screens in the control room, when the physicists traditionally hand over champagne to the accelerator crew. “There are quite a number of bottles there,” says Mnich. Empty, of course.

© dpa-infocom, dpa: 220102-99-563332 / 2