CERN Scientists Achieve Historic Control Over Antimatter Particles

Scientists at the European Organization for Nuclear Research, known as CERN, have reached a major milestone in understanding the universe. An international team of researchers successfully controlled the spin of a single antiproton for the first time. This achievement is part of the Baryon Antibaryon Symmetry Experiment, or BASE. It helps scientists study antimatter, which is one of the biggest mysteries in modern physics. Dr. Jack Devlin, a researcher from Imperial College London and a member of the BASE team, explained the importance of this work. He noted that while scientists have controlled atoms and molecules for a long time, doing so with antimatter is much harder. This new level of control allows researchers to look closely at the fundamental properties of these rare particles. The team’s work was recently recognized as a top breakthrough by the publication Physics World. Antimatter is often described as a mirror image of normal matter. An antiproton has the same mass as a regular proton but carries an opposite electrical charge. When matter and antimatter meet, they destroy each other in a flash of energy. Because of this, antimatter is extremely difficult to store and study in a laboratory setting. To study the antiproton, the team used a device called a cryogenic Penning trap. This tool uses cold temperatures and strong electromagnetic fields to hold the particle in place. By isolating the antiproton from its surroundings, the scientists could keep it stable for a very long time. In some cases, these particles can be held for months or even years inside the trap. The researchers focused on a property called spin, which makes the particle act like a tiny magnet. This spin can point in two different directions, which scientists call a two-level system. By using carefully tuned electromagnetic fields, the team was able to make the spin flip back and forth. This process is known as coherent control, and it is essential for making precise measurements. One of the most impressive parts of the experiment was how long the control lasted. The team demonstrated that the antiproton’s spin remained stable for more than 50 seconds. This is a long time in the world of subatomic particles and allowed the team to observe many spin flips. This stability is a key requirement for the next generation of physics experiments. This research aims to answer a fundamental question about why the universe exists. According to the Standard Model of physics, the Big Bang should have created equal amounts of matter and antimatter. However, almost everything we see today, from stars to people, is made of matter. Scientists are searching for any tiny difference between the two that might explain why matter won out. By controlling the spin, the BASE team can now measure the antiproton’s magnetic properties with much higher accuracy. Specifically, they are looking at the g-factor, which is a value that describes how the particle reacts to magnetic fields. The new technique is expected to be at least 16 times more accurate than previous methods. Even a tiny difference in the g-factor between protons and antiprotons could change our understanding of physics. The project involves a large collaboration of scientists from around the world. In addition to CERN and Imperial College London, researchers from several other institutions contributed to the findings. This global effort shows how complex and important the study of antimatter has become. The results were first shared in the scientific journal Nature before receiving wider recognition. Looking ahead, the BASE team plans to use these new tools to perform even more sensitive tests. They want to see if the laws of nature treat matter and antimatter exactly the same way. If they find a discrepancy, it could lead to a new theory that goes beyond the Standard Model. For now, the ability to steer an antiproton marks a historic step forward in quantum science. This breakthrough is part of a larger program at Imperial College London called Quantum Tests of Fundamental Physics. This program uses advanced technology to probe the most basic principles of the natural world. By combining engineering and physics, researchers hope to unlock the secrets of the early universe. The success of the BASE experiment provides a clear path for future discoveries in this field.