They are able to easily cross the galaxy and reach the Earth, the antimatter particles produced by dark matter, i.e. the mysterious matter that makes up 25% of the universe and whose composition is unknown.
This is indicated by the experiment carried out at Cern with the Alice detector, one of the four great experiments of the LHC accelerator and to which Italy has made an important contribution, with the National Institute of Nuclear Physics (INFN).
Published in the journal Nature Physiscs, the result suggests that experiments conducted in space such as AMS-2, installed outside the International Space Station, are perfect for hunting dark matter.
"We know that dark matter is made up of particles with mass and that the density of this form of matter is greatest at the center of galaxies," said Andrea Dainese, Alice's physics coordinator and researcher in the Padua Infn section.
Almost nothing is known about the nature of dark matter yet, but it is hypothesized that under certain circumstances it could produce antinuclei, i.e. antimatter particles that could travel through space up to us.
"Since there are very few 'natural' sources of antimatter, for example cosmic rays, any antinuclei arriving from the center of the galaxy - said Dainese - would be indicators of the presence of dark matter and could reveal some details of its nature".
But in order to intercept these signals, it would first of all be necessary to understand if and how these antiparticles can actually travel hundreds of light years without destroying themselves by interacting with ordinary matter in a process of annihilation.
And that's what was done at Cern, with the Alice experiment, which estimated the number of antinuclei that could be able to cross the galaxy to reach Earth.
