Scientists Trapped an Antimatter Particle for Months to Study Its Secrets
Northwestern researchers have developed a device that can hold a single positron, an antimatter particle, in a vacuum for months without destroying it. Keeping the particle available for repeated experiments could help scientists investigate why the observable universe is made mostly of matter, despite antimatter being expected to exist in similar amounts.
The device uses electric and magnetic fields to trap the positron at a temperature close to absolute zero, leaving it in its lowest energy state so researchers can make controlled changes to its quantum behaviour. The method could make measurements of antimatter around 30 times more precise than before, particularly comparisons of the magnetic properties of positrons and electrons. So far, the experiment has found no unexpected differences between them.
In short
- A new device held one positron for months.
- It could improve antimatter measurements by about 30 times.
- Researchers have not found unexpected differences from electrons.
Explained simply
Positrons are the antimatter counterparts of electrons: they have the same mass but a positive electric charge. When a positron meets an electron, the two can annihilate, turning their mass into energy, so studying antimatter requires careful control of the conditions.
Physicists use trapped particles to measure their properties and compare them with those of ordinary matter. The standard picture of the early universe suggests matter and antimatter should have been produced in similar amounts, but the observable universe is now mostly matter. Researchers including teams at Northwestern University study particles such as positrons to look for small differences that might help explain this imbalance.