Two physicists from the University of California, Davis have got a new element for the position of dark matter and also a possible way for its detection. Their work was presented on June 6 at the Planck Conference which was held in Granada, Spain and it has also been submitted for publication in the near future.
It is estimated by researchers that dark matter comprises about a quarter of our universe, while the rest is composed of dark energy which is even more mysterious in the scientific world. Although it cannot be observed in a direct manner like normal matter, its presence can be detected through its gravity which helps in determining the shape of very distant galaxies and other such entities.
According to many researchers, dark matter is composed of an element which is yet to be identified. However the Weakly Interacting Massive Particle or WIMP has been considered as the most likely candidate for some time now. There is no clear cut definition of WIMP but it is broadly defined as a new type of elementary particle that interacts through gravity and other forces and is weaker than the weak nuclear force. Inspite of many efforts to detect it, WIMPs have not been observed in the experiments.
John Terning, a physics professor at UC Davis, who is also a coauthor of the paper said that it is not yet known for sure what is dark matter. Although WIMP was a candidate for a long time, it has been mostly ruled out. An alternative to the WIMP model is a kind of “dark electromagnetism” which includes elements such as “dark photons” and other types of particles.
In the paper, Terning along with fellow researcher Christopher Verhaaren provided a twist to the concept. It consists of a dark magnetic “monopole” interacting with dark photon. Monopole is a type of element which behaves like one end of magnet. Scientists hypothesize that dark monopoles interact with dark photons and dark electrons similar to the interaction of electrons and photons with monopoles.
The Aharonov-Bohm effect is the interference pattern in which electron when moving by a magnetic field is influenced by it while not passing through the field itself. Terning and Verhaaren remarked that a dark monopole can be detected because of the nature of shift of electrons while passing.
In a theoretical sense, the dark matter elements are passing around us all the time but to be detected in the model suggested by Terning and Verhaaren, they would have to be excited by sun. However the predicted phase shift is very small, smaller than value needed for detection of gravity waves.