There is a certain appeal to what is dark that humans find captivating. “Dark” matter is no exception. It appears that the more scientists reach out to understand it, the more evasive it demonstrates itself to be. In an attempt to shed light on its nature, a new theory has seen the light of the day: according to the hypothesis, dark matter behaves in similar ways to subatomic particles. The findings have been published in the journal Physical Review Letters.
While the occurrence of dark matter has not been proven, scientists insist on its existence. According to them, dark matter keeps whole galaxies, stars, the solar system, and our own bodies intact. What to make of something that has never been observed? Does it indeed really exist? Well, an international team of researchers have gone forward, beyond assessing its presence, to proposing a theory that dark matter bears close resemblance to pions which are known to cause atomic nuclei to bind together.
“We have seen this kind of particle before. It has the same properties – same type of mass, the same type of interactions, in the same type of theory of strong interactions that gave forth the ordinary pions. It is incredibly exciting that we may finally understand why we came to exist,” says Hitoshi Murayama, Professor of Physics at the University of California, Berkeley, and Director of the Kavli Institute for the Physics and Mathematics of the Universe at the University of Tokyo.
The new theory explains that dark matter might interact with itself in the midst of galaxies, or clusters of galaxies, and modify the predicted mass distributions while at it.
Artist’s impression of dark matter distribution.
The left image depicts the conventional dark matter theories, showing dark matter peaked in a small area in the centre of a galaxy. The right image illustrates the spreading out of dark matter from the centre. Photo credits: NASA, STScI; Kavli IPMU – Kavli IPMU modified this figure based on the image credited by NASA, STScI.
“It can resolve outstanding discrepancies between data and computer simulations,” says Eric Kuflik, a postdoctoral researcher at Cornell University.
University of California, Berkeley postdoctoral researcher Yonit Hochberg adds, “The key differences in these properties between this new class of dark matter theories and previous ideas have profound implications on how dark matter can be discovered in upcoming experimental searches.”
The theory yet has to be tested. The Large Hadron Collider and the SuperKEK-B, together with a proposed experiment SHiP might potentially be used to do so.