The universe is full of matter of all types – even some antimatter. The difference between these two is like looking in a mirror; you are seeing exactly what it is, but in reverse. Matter is made of particles, while antimatter is made of antiparticles. What categorizes something as an anti-version is the opposite electric charges and other quantum properties. At the beginning of the universe, both parts were almost equal, but billions of years later, the anti-version of regular matter is almost a myth, but very present in our daily life.
The use of antimatter in daily life
Antimatter can be produced in the lab using high-energy collisions between particles to create this type of matter, so scientists can study it. On the other side, bringing it to our daily use, medics harness it through PET scans — using positrons to track activity inside the body and detect diseases like cancer with incredible precision.
The way it works is that the tracer — a radioactive substance that emits positrons (the antimatter version of the electron) — is injected into the patient’s body. The substance travels through the bloodstream and accumulates in areas where high chemical activity is happening, like cancer cells.
When a positron meets an electron in the body, they annihilate each other, producing two gamma rays that fly in opposite directions, which the PET scanner detects to create detailed images. Now, scientists have found something that should not exist: a strange type of antimatter, causing a lot of buzz in the scientific field.
Strange antimatter found in experiment using CERN’s most powerful tool
Scientists at CERN, using the ALICE experiment, have spotted something quite rare: the antimatter version of hyperhelium-4. This unusual type of antimatter has its nucleus made up of two antiprotons, one antineutron, and an antilambda. Like a neutron, this antimatter nucleus carries no electric charge.
They created it by smashing lead atoms together at very high speeds inside the Large Hadron Collider (LHC). While this finding hasn’t reached the strict level of certainty physicists usually require to call it a full discovery (it sits at 3.5 sigma, whereas 5 sigma is the gold standard), it still fits well with current physics models, including the Standard Model.
This antimatter nucleus is formed in a quark-gluon plasma — a super-hot and dense state of matter that existed just after the Big Bang. In this plasma, rare particles called hypernuclei can form; these aren’t just made of protons and neutrons, but also include hyperons, which contain a “strange” type of quark.
How could this discovery help scientists?
Finding this helps researchers test ideas about why the universe today is made mostly of matter, and not its antimatter counterpart. Right after they’re created in particle collisions, antihypernuclei last only for a tiny fraction of a second — just billionths of a second — before breaking down into smaller particles that scientists can spot.
The very first antihypernucleus ever found was called antihypertriton. It’s made of an antiproton, an antineutron, and an antilambda — basically antimatter versions of normal particles. Scientists discovered it back in 2010 at Brookhaven’s RHIC by smashing gold atoms together.
Looking back at old research
More recently, in 2024, that same lab spotted antihyperhydrogen-4, which is like a heavier cousin, having one more antineutron than the antihypertriton. Now, researchers at CERN’s ALICE experiment took a fresh look at some older data from 2018, when lead ions were smashed at very high speeds. Using machine learning to analyze the particles produced, they found the first ever evidence of antihyperhelium-4 — the first time this particular antimatter hypernucleus has been spotted at the LHC. This could lead to new discoveries, as CERN is one of the most important scientific facilities in Europe.