A new particle for dark matter
A group of researchers at the University of Southampton has proposed the existence of a fundamental particle to explain the nature of the enigmatic dark matter. It is a new experimental approach in space that attempts to shed light on an unknown sector where it is expected that these particles may exist.
Researchers from the University of Southampton have proposed for the dark matter of the existence of a new candidate, which is a fundamental particle that could explain why it was not possible to reveal this elusive component that represents about 85% of the mass of universe.
Credit: J. Bateman et al. 2015/Nature
Dark matter exerts a gravitational effect on the stars and galaxies, through a phenomenon predicted by general relativity, known as gravitational lens that causes the bending of light rays from distant objects, and leaves its tracks imprinted in the cosmic microwave background, the residue fossil of the Big Bang.
Despite several attempts have been made experimental, none so far has revealed the dark matter directly. Particle physicists provide us with clues about its nature and, according to the most common thought, it is believed to be characterized by “heavy particles” whose mass is comparable with that of the heavier atoms. Instead, the lighter particles are considered less attractive for some astrophysical reasons, although there are exceptions. However, starting from general arguments of particle physics, this study sheds light on an unknown sector where it is expected that such candidates may exist.
The particle in question would have a mass of 100eV / c2, the value of which is equal to 0.02 percent of that of the electron. While it does not interact with the light, as it is required for the particles that constitute the dark matter, it interacts strongly, and surprisingly, with ordinary matter. In fact, this particle may not penetrate the Earth’s atmosphere, in sharp contrast to the other candidates, which excludes a possible mechanism of detection with the use of instruments to Earth. Therefore, researchers are planning to move in space through the Macroscopic Quantum Resonators (MAQRO) consortium, where they are already involved. The experiment is to observe the recoil of a test particle suspended in space and exposed directly to the incident flux of dark matter particles that will in turn spread. In this way, the instruments sensitive to the position of the particle test will provide scientists with valuable clues about the nature of this new candidate χ, if it really exists.
James Bateman, Department of Physics and Astronomy and co-author of the study, explains: “This work brings together some very different areas of research: particle physics, astronomy, X-band and quantum optics. Our particle seems a bit “crazy” though it does not exist at the time of experiments or observations that may exclude its existence. Dark matter is one of the most important problems of modern physics, and we hope that our hypothesis will inspire other researchers to develop a theory that can be experimentally verified. ”
Merle Alexander, of the Max Planck Institute in Monaco, in Germany, and co-author of the study, adds: “For now, the experiments on dark matter do not point in a clear direction and, as the Large Hadron Collider did not find any significant signal that can be traced back to a new physics it might be the time to consider our thinking on other candidate particles. As the physics move towards this path, our idea becomes more and more competitive. ”
“From this point of view, our work represents a milestone in our department: for the first time there is a publication that involves authors from three different groups of physics and astronomy, and shows how valuable it can be to cross borders and look beyond their own field of research”, concludes Bateman.