Physicists have caught an elusive 4D ghost in the CERN particle accelerator

According to a study published in the journal Nature Physics, physicists were finally able to get a good look at an invisible structure at CERN’s particle accelerator called the Proton Super Synchrotron. This structure can change the course of a beam of particles and create problems for scientists when studying these particles, writes ScienceAlert.

This structure is described as one that occurs in a phase space representing one or more states of a system that is moving. To display a structure, four states are needed, and therefore it is considered as four-dimensional.

This invisible structure arises from a phenomenon called resonance, and the ability to measure and quantify it brings physicists closer to solving a universal problem for magnetic particle accelerators.

According to scientists, due to resonances, particle beams do not move in the direction that scientists want, and then the particles scatter and disappear. Thus, this leads to a deterioration in the quality of the particle beam and it becomes more difficult to obtain the desired beam characteristics.

The phenomenon of resonance occurs when two systems interact and synchronize. For example, planets can experience orbital resonance when there is a gravitational interaction between two worlds while rotating around a star.

Particle accelerators use strong magnets to create electromagnetic fields that help direct beams of particles in the direction physicists want. But due to imperfect magnets in particle accelerators, resonances can occur, which leads to the creation of a magnetic structure that interacts poorly with particles.

A dynamical system is much more difficult to describe mathematically if it exhibits more degrees of freedom. Typically, two degrees of freedom are used to describe the motion of particles in an accelerator, that is, it shows two spatial coordinates that are necessary to determine the position of particles on a plane.



Source: Press photo

But to describe the structures in the accelerator, you need to use additional functions of phase space, that is, you need measurements not only of up-down and left-right movement, but you need four parameters to display the particle in space. According to physicists, to create a resonance map, you need to measure the particle beam in both horizontal and vertical planes.

To understand the effect of resonance on a beam of particles in an accelerator, scientists took several years and had to use computer simulations. But the information received made it possible to finally measure the magnetic anomaly.

Physicists observed the position of a beam of particles at the Proton Super Synchrotron and were able to measure the position of particles for approximately 3 thousand beams. The resonance map in the accelerator was created by measuring how the particles are located – closer to the center or whether they are shifted to one side.

According to the authors of the study, the new discovery is very important, because it was possible to show how individual particles behave in a coupled resonance. It was also possible to show experimentally that the theories and models predicted everything correctly.

Now physicists want to create a theory that will describe the behavior of individual particles in the presence of resonance in an accelerator. This will help reduce particle launch disruption and produce more accurate beams. This has critical implications for both current experiments and future particle accelerator research.