An Antimatter Experiment Shows Surprises Near Absolute Zero

Researchers have been searching for new laws of physics for decades. The laws would come in the form of forces or other phenomena that favor matter over antimatter. Physicists have not found a conclusive sign that antimatter particles are different from other particles.

That hasn't changed. One team stumbled upon a puzzling finding while pursuing precision antimatter experiments. The atoms made from matter and antimatter behave differently when bathed in liquid helium. The properties of most atoms would be thrown into disarray by buffeting from the stew. The research team spent years checking their work and arguing about what happened after the discovery. The group detailed their findings in Nature.

Mikhail Lemeshko, an atomic physicist at the Institute of Science and Technology Austria, was not involved in the research. He thinks that the result will lead to a new way of looking at things.

Antiprotons.

One way to gauge the properties of atoms and their components is to tickle them with a laser and see what happens. An electron can be pushed to a higher energy level by a laser beam with just the right energy. The electron emits light when it returns to its previous energy level.

In an ideal world, experimentalists would see every single hydrogen atom shining with the same colors. Natural constants such as the electron's charge or how much lighter the electron is are revealed by an atom's spectral lines.

Our world is flawed. In chaotic ways, atoms careen about each other. The host atom's energy levels are affected by the constant jostling of the atoms. Each atom will respond in a different way if a laser is shone at the distorted particles. The cohort's colors get lost in the rainbow.

Hori is a strontium practitioners who spends their careers fighting this. They might use thinner gases where atomic collisions will be less frequent.

At the time a graduate student of Hori was working on a hobby project, it initially seemed counterintuitive.

The antimatter experiment was done at the CERN laboratory. The group would make hybrid matter-antimatter atoms by firing antiprotons. An antiproton can sometimes take an electron from a helium nucleus. There was a small group of atoms.