One of the biggest mysteries of our universe is what is dark matter made of. Its existence is suggested by several astronomical observations, among them peculiarities in the rotation of galaxies. Dark matter would have to make up at least 63% of all matter in the universe and to date, physicists have no idea about its exact nature.
All that is clear is that dark matter interacts with normal matter only via gravity. These could be, among other things, so-called WIMPs (Weakly Interacting Massive Particles), which would be considered cold dark matter. However, researchers are not making very quick progress on their search for these particles. To date, they have only been able to rule out more and more possible candidates, which is gradually making it more and more unlikely that they are actually on the right track.
Now, in an article in the Journal of Physics, researchers have presented a new candidate. This is a so-called hexaquark: a particle consisting of six quarks, the basic building blocks of many elementary particles. Three up and down quarks, its lightest variants, combine to form a d*(2380) hexaquark. For a long time, hexaquarks were considered hypothetical; in 2014, the first was discovered, d*(2380), at the Jülich Research Center. d*(2380) has a mass of 2380 MeV and is thus heavier, but due to its structure, more compact than a proton, the nucleus of a hydrogen atom.