One particle at a Time: Shining a Light on Dark Matter

Experts from the University of Adelaide are working to uncover the secrets of dark matter.

One particle at a Time: Shining a Light on Dark Matter

Experts from the University of Adelaide are working to uncover the secrets of dark matter. This 84% of all matter in the universe is unknown. Researchers have developed a new tool to detect the existence of a new particle.

Professor Anthony Thomas, Elder Professor of Physics at the University of Adelaide, stated that "We are trying solve the problem of understanding one of modern science's grand challenges--how do we find what kind of particle dark matter it is made of?"

"Dark matter is five-times more abundant than visible matter, which physicists have so successfully explored and of which we are made.

"We don't know what particle makes up dark matter, but we want to, along with many others around the globe, to figure this out."

Professor Thomas is part of the ARC Center of Excellence for Dark Matter Particle Physics team that aims to uncover more about this mysterious substance.

The Sodium Iodide and Active Background Rejection Experiment is one key approach. It is currently being constructed in a laboratory located in a former goldmine, just 1 km underground in Stawell (Victoria). This experiment is being developed in collaboration with researchers from Australia, Europe and the United States. It will hopefully provide answers to this question in a few years.

Professor Thomas and Dr. Xuangong Wu, both from the University of Adelaide's School of Physical Sciences published their latest work in the journal Physical Review Letters. It explores the possibility of dark matter in the form of a dark huge photon.

Professor Thomas stated that "we are currently exploring the discovery potential for a new tool parity violating electron scattering which has been enabled through the upgrade at Thomas Jefferson National Accelerator Facility(JLab) in The United States."

Paraity violation is like looking at what happens in the lab and what happens when it's viewed in a mirror. These differences are usually less than one part per million. However, we can observe them and use them as a signal that this new particle exists.

"We discovered a strange result regarding the size of a nucleus of lead. This may be explained if there's a new particle of dark matter, the dark photon.

"Experiments where predictions are not affected by dark matter can be altered by up to five percent. This difference provides direct evidence of this type.

Professor Thomas's research may provide insight into the mysterious discrepancy between the neutron density of a lead nucleus versus that predicted by nuclear structures theory.

He said, "Future experiments on the behavior of electrons and positrons could provide a vital test for the existence of such an particle."

Visible matter is only the tip of an iceberg. We will be able to see the secrets of our universe through a better understanding dark matter, which is the sub-surface of the iceberg.