The heaviest antimatter particle ever detected

The discovery is the first evidence of the heaviest antimatter hypernucleus ever found in the world. Large Hadron Collider (LHC).

Inside the Large Particle Collider (LHC), a circular underground tunnel 27 km in circumference on the French-Swiss border, a team of scientists accelerated subatomic particles to speeds close to that of light.

These collisions caused, for fractions of a second, the same conditions that existed in the Universe shortly after the Big Bang.

Among the many observations arising from the experiment, the international ALICE collaboration recently announced the first evidence of anti-hyperhelium-4which is composed of two antiprotons, an antineutron and an antilambda.

According to , this is the first observation of the heaviest antimatter hypernucleus no LHC.

The equivalent of antihyperhelium 4 is not ordinary matter, but an exotic baryonic particle. It is a form of hypernucleus, composed of particles called hyperions, which means that hyperhelium-4 is not a particle composed only of protons and neutrons, but a “modified” version of helium-4, an isotope of helium.

Helium, which is the second lightest and most abundant element in the Universe, has a nucleus with two protons and two neutrons, with two electrons spinning around it. Protons and neutrons are made up of three quarks: while protons have two up quarks and one down quark, neutrons have one up quark and two down quarks.

In addition to these types of quarks, there are others, such as strangem which, when combined with two other quarks, forms a hyperon, a particle similar to a neutron and proton, but heavier.

Despite being unstable, hyperons have a useful life that allows them to unite with protons and neutrons, thus forming the hyperhelium-4composed of two protons, a neutron and a lambda hyperon.

During their search for hiernuclei, scientists used machine learning to identify signs and found solid evidence that they actually existed. Interestingly, ALICE experts found no proof of the existence of hyperhelium-4, but rather its antimatter equivalentanti-hyperhelium-4, composed of two antiprotons, an antineutron and an antilambda.

To do this, physicists observed the decay products of antihyperhelium-4, that is, an antihelium-3 nucleus, an antiproton and a charged pion.

Until now, scientists didn’t know whether antimatter hypernuclei could exist. Antihyperhelium-4 is the first of its kind ever observed.

As it is an extremely rare and exotic form of antimatter, the study of this hypernucleus can help to deepen the understanding of these oppositely charged particles.

The scientific article was published on arXiv, but still needs peer review.