Hypotheses about dark matter are plenty, but what we know so far about it is that it generates more mass the astronomers cannot directly identify yet. They know it exists because it has a gravitational impact on things they can detect, but they do not know what exactly the dark matter actually is and how it got there.
Now, though, scientists have just detected a particle that could be behind it. The prospect is a recently found subatomic particle dubbed d-star hexaquark, which, in the primitive darkness after the Big Bang, could have gathered to create dark matter.
On a Quest to Find More About Dark Matter
For about a century, dark matter has puzzled researchers. It was first observed in the vertical movements of stars, which suggested that there was more mass surrounding them that what scientists could see.
The impact of dark matter in other dynamics can also be seen now, for instance, in gravitational lensing, in which light bends around gigantic objects such as galaxy clusters, and the external orbit of galactic disks, which is way too fast to be clarified by visible mass.
Dark matter has, until now, proven impossible to identify directly, as it doesn’t absorb, transmit, or reflects any type of electromagnetic radiation. However, its gravitational impact is powerful; in fact, so strong that about 85 percent of the matter in the Universe could be dark matter.
Researchers are hoping to understand the dark matter because this could tell a lot about the way the Universe took shape and the way it works. There have been a few dark matter candidates suggested over the years, but there’s still far from an actual answer. This is where the d-star hexaquark, also known as d*(2380), comes up.
“The origin of dark matter in the Universe is one of the biggest questions in science and one that, until now, has drawn a blank,” explained nuclear physicist Daniel Watts of the University of York in the UK. “Our first calculations indicate that condensates of d-stars are a feasible new candidate for dark matter. This new result is particularly exciting since it doesn’t require any concepts that are new to physics.”
Quarks are basic particles that normally mix in groups of three to create protons and neutrons. Together, these three-quark particles are called baryons, and most of the visible matter in our Universe is made of them, including humans, the Sun, the planets, and space dust.
When six quarks mix, it creates a kind of particle known as dibaryon or hexaquar. Researchers have not actually seen many of these particles at all.
The More Condensates There Are, The Closer to an Answer
D-star hexaquarks are bosons, a kind of particle that respects Bose-Einstein statistics, a structure for explaining how particles act. In this situation, it means that groups of d-star hexaquarks can create something known as Bose-Einstein condensate.
These condensates are created when a low-density gas of bosons cools down to above absolute zero. By then, the atoms in the gas change from their regular wobbling and jiggling to quite still, the lowest quantum state that exists.
If such as gas of d-star hexaquarks was moving around in the young Universe as it cooled after the Big Bang, as per researchers’ pattern, it could have merged to form Bose-Einstein condensates. Those condensates could be what we know as dark matter. Of course, everything is highly hypothetical, but the more dark matter prospects there are, the closer we are to understanding what dark matter is.
There is still a lot of work to be done here. The researchers plan to search for d-star hexaquarks in space and to analyze their current work to see if they can violate it. They also intend to carry out more research on d-star hexaquarks in the lab.
“The next step to establish this new dark matter candidate will be to obtain a better understanding of how the d-stars interact – when do they attract and when do they repel each other,” said the University of York physicist Mikhail Bashkanov. “We are leading new measurements to create d-stars inside an atomic nucleus and see if their properties are different to when they are in free space.”
The study has been published in the Journal of Physics G: Nuclear and Particle Physics.