Physics: CERN: The particle accelerator will soon be back in full swing – the science

GENEVA (dpa) – The world’s largest research facility will soon return to its highest standard. The giant particle accelerator at the European Organization for Nuclear Research (CERN) in Geneva will restart from the end of March 2022 after a three-year maintenance outage.

Starting in June, the proton beams will be chased back against each other at nearly the speed of light in the 27-kilometre underground ring in order to cause collisions. Physicists hope for ground-breaking new discoveries, says director of research Joachim Menich of the German Press Agency.

The particle accelerator, completed in 2008, simulates time shortly after the Big Bang, the birth of the universe about 14 billion years ago. Researchers search for the fundamental laws of the universe and investigate the smallest components of matter, the elementary particles. For this purpose, the particles are collide in order to observe the resulting decomposition processes. Among other things, in 2012 at CERN it was possible for the first time to detect the Higgs boson, theoretically described more than 40 years ago, which gives other elementary particles their mass. It was considered the final piece of the puzzle in the Standard Model of particle physics.

improve the performance

In the context of inventory, the performance of the accelerator and connected detectors has been greatly improved. The number of collisions recorded should be twice what it was before. “We get access to very rare processes. The more collisions there are, the more accurate the results,” says Mnich.

There are two areas in which we can expect particularly exciting results in the near future, explains Mnich, who was long before his appointment at the beginning of the year as director of particle and astroparticle physics at the German Institute of Electron Synchrotron (Desy).

At one research facility, LHCb, observations were made this year for the first time that differ from the Standard Model of Physics, which describes twelve substances and their interactions. The so-called beauty quarks did not decay into muons and electrons in equal parts, as expected. Mnich says the cause of the effect may be a previously unknown force of nature. However, monitoring must be done more often in order to have security.

“Hopefully, we can clarify the question of whether this is a real or a statistical mirage in the next couple of years. That will be quite a sensation. We will then have clear evidence for the first time that the Standard Model is incomplete and does not describe all phenomena.”

Upgrade “Elena” decelerator

A new era has also begun for antimatter experiments, says Minich, “perhaps with surprises.” The ‘Elena’ (extremely low-energy anti-proton ring) decelerator, which went into operation in 2017, was upgraded during the maintenance phase. In it, the antiprotons are slowed down so that they can be better captured and observed. “We’re looking at the question: does antimatter fall like regular matter, or does it fall?” Mnich says. Gravity is a very weak force at the level of sub-atoms, so it takes a long time to prove it.

What does all this bring to people? “Of course it is always a gain in knowledge,” says Mnich. “We try to understand what holds the world together, and how nature works.” Particle research has already brought a lot of tangible benefits. “It wasn’t clear at the time that discovering how atoms worked 100 years ago would lead to the development of the cell phone.” Among other things, the devices and processes developed at Cern are used in medicine, especially in the treatment of cancer and the fight against tumors. We should not forget the Internet, as the then-cern computer specialist Tim Berners-Lee established the foundation 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, when the so-called HiLumi phase begins thanks to additional expansions: then it will produce five to ten times more proton collisions per second than today and thus generate more data that scientists can evaluate . Until then, stronger magnets must be developed that focus proton beams more strongly at the collision points. “Prototypes already exist, but not all quality standards have been met,” Mnich says.

A larger accelerator concept was on the table in the 1940s: a 100-kilometre loop instead of the previous 27-kilometre. Feasibility studies for this have been underway since the summer. With its current particle accelerator, Cern is a world leader, but there are also ambitious plans in Japan, especially in China.

Cern’s next champagne bottles will now be refrigerated in June 2022. Then, two months after the accelerator’s micro-startup, the accelerator must be completed. “It’s not like a car: turn the switch and then turn it off,” Mnich says. The smallest errors can destroy devices worth millions. When the first collisions occur in June, that can be seen on screens in the control room, when physicists traditionally deliver champagne to the accelerator crew. “There are quite a few bottles,” says Mnish. Empty of course.

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