A new discovery could finally shed light on a persistent cosmological mystery.
The heaviest antimatter nucleus ever detected has been observed: antihyperhydrogen-4. Consisting of an antiproton, two antineutrons, and an antihyperon, this nucleus was identified among the traces left by billions of collisions within the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in New York.
This discovery is of great importance to physicists who are striving to understand why our Universe is dominated by matter even though cosmological theory predicts an equal creation of matter and antimatter at the time of the Big Bang. According to the standard model, these two forms of matter should have annihilated each other, leaving behind an absolute void.
To explore this enigma, researchers have recreated conditions similar to those of the Big Bang by colliding heavy ions at high speeds. These collisions produce a soup of plasma where primordial elements, including antihyperhydrogen-4, temporarily emerge before vanishing almost instantaneously.
By analyzing the traces left by these ephemeral particles, scientists discovered 16 nuclei of antihyperhydrogen-4. Notably, the lifespan of these particles does not seem to differ from that of their matter equivalent, hyperhydrogen-4. This, for now, confirms the validity of current particle physics models.
However, the researchers are not stopping there. The next step will involve comparing the masses of particles and antiparticles to detect any potential asymmetries. Such a discovery could provide valuable clues about the origin of matter's dominance in the Universe.
The results of this study promise new perspectives in our quest to understand the Universe, potentially challenging some fundamental aspects of physics.
What is antimatter?
Antimatter is a form of matter composed of particles with charges opposite to those of ordinary matter particles. For example, the antiparticle of the proton is the antiproton, which has a negative charge instead of positive. Antimatter particles are identical to their matter counterparts in terms of mass and spin, but their electric charges are reversed.
When a particle of matter meets its antiparticle, they annihilate each other, releasing a large amount of energy in the form of photons, particularly gamma rays. This matter-antimatter annihilation phenomenon is one of the reasons antimatter is rarely observed in the current Universe.
Antimatter is crucial for research in physics because it might hold key clues to explaining why our Universe is dominated by matter, even though matter and antimatter were expected to be produced in equal quantities during the Big Bang.