A completely new type of fundamental particle could help explain the mystery of the dark matter, which makes up over 80 percent of the mass of the universe.
James Bateman from the University of Southampton in the UK, together with colleagues, have proposed that this particle could provide an explanation as to why no one has yet managed to detect and directly observe the dark matter, which is believed to exist based on its gravitational effects on the galaxies and stars, the bending of light rays and its Cosmic Microwave Background (CMB) imprint.
It is believed that dark matter particles have very big mass for fundamental particles but the new research, which was published in Scientific Reports on Jan. 27, proposed that the reason why dark matter remains elusive is that its particles are much lighter than what scientists think.
The hypothetical particle that Bateman and colleagues have proposed has a mass of 100eV/c^2, which is approximately only 0.02 percent of an electron's, and although it does not interact with light, it interacts strongly with normal matter.
Unlike other dark matter candidates, the yet unnamed particle may not also be able to penetrate our planet's atmosphere because of its infinitesimally small mass, which could help explain why dark matter particles are not detected by Earth-bound detectors.
"Our candidate particle sounds crazy, but currently there seem to be no experiments or observations which could rule it out," Bateman said. "Dark matter is one of the most important unsolved problems in modern physics, and we hope that our suggestion will inspire others to develop detailed particle theory and even experimental tests."
Study co-author Alexander Merle from the Max Planck Institute said that current experiments involving dark matter do not have a clear direction and since CERN's Large Hadron Collider has not yet found new physics signs, it could be time to shift the paradigms toward alternative dark matter candidates. He said that their proposed light dark matter particle could be a serious competitor among these candidates.
"Here we present a novel form of low-mass DM (Dark matter) χthat would have been missed by all experiments so far," the researchers wrote. "While its large interaction strength might at first seem unlikely, neither constraints from particle physics nor cosmological/astronomical observations are sufficient to rule out this type of DM."
Although scientists acknowledge the importance of dark matter in the evolution of the universe, the material remains a total mystery.
