Physicists trapped a positron for months, a breakthrough that could test CPT invariance with unprecedented precision.
Positron confinement achieved for months
Physicists have managed to trap a positron, the antimatter counterpart of the electron, for several months using a superconducting vacuum cryogenic trap. This marks a significant breakthrough in antimatter research.Positron and electron annihilation
A positron can annihilate with an electron, releasing energy. This process is a key reason why the universe is dominated by matter rather than antimatter, though the exact reason for this imbalance remains a mystery.Universe's matter-antimatter puzzle
The early universe is thought to have produced equal amounts of matter and antimatter, but if that were true, they should have mostly annihilated each other, leaving little matter. Scientists are still unsure why the universe exists as it does, with matter dominating.Elementary particles for experiments
Electrons and positrons are elementary particles, unlike protons which are made of quarks. This makes them ideal for creating controlled environments to study fundamental symmetries, like charge-parity symmetry violation.Isolating positrons is complex
Positrons are produced in high-energy processes and quickly annihilate with electrons. This makes isolating them extremely difficult, as any contact with electrons leads to their destruction.Producing and slowing positrons
Researchers used a radioactive isotope of sodium, sodium-22, to produce positrons. These positrons, with high energy, were slowed down using a tungsten single crystal, allowing them to be captured in a trap.Positronium and the trap
Some positrons formed a bound state with electrons called positronium. This state allowed the positron to be extracted from the crystal and placed into a trap, which used magnetic and electric fields to keep it confined.CPT invariance and future research
The next step is to measure the magnetic moment of the positron and compare it to the electron’s. If they are the same, it would be the most precise confirmation of CPT invariance in the Standard Model, according to the lead researcher. Results are expected early next year.
