A small particle, the neutrino, can potentially destroy itself. That may be the explanation for the presence of matter in the universe.
When the universe came into existence with the big bang 13.8 billion years ago, according to the theory, as much matter as antimatter was formed.
Matter is what makes up our own body and everything around us. Antimatter is made up of particles with opposite properties. A proton is canceled by an antiproton with an opposite charge, and the opposite pole of an electron is a positron.
When matter and antimatter meet, they wipe each other out while emitting a large amount of energy. Thus, by far the most matter and antimatter disappeared shortly after the big bang.
In fact, everything should have disappeared, and it is one of the greatest puzzles in physics how something could remain that shaped stars, galaxies, and planets.
Ghost Particle is its own opposite
According to some physicists, the solution lies with the neutrino, a spooky particle. Perhaps it is his own anti-particle, which can explain how the imbalance between matter and antimatter could arise in the young universe.
Scientists have repeatedly tried to solve the mystery with experiments, and now they are trying again with the GERDA detector in the mountains of Gran Sasso in Italy.
They will investigate the radioactive decay of a special variant of the element germanium.
Rare decline clarifies mystery
During the decay, a neutron in the atomic nucleus turns into a proton, releasing an electron and an antineutrino. In rare cases this happens twice and two antineutrinos are released.
If the two particles immediately cancel each other out, so that they cannot be measured, anti-neutrinos and neutrinos must be the same. If so, we know where matter in the universe comes from.
Scientists catch volatile particles
The test must take place in a huge detector 1400 meters below ground. Water, copper and liquid argon ensure that the measurements are not disturbed by ambient radiation.