New insights into dark matter have emerged as researchers explore the “dark photon” hypothesis, posing certain challenges to the standard model. Led by experts at the University of Adelaide, an international group of researchers has uncovered additional clues in their deep investigation into the nature of dark matter.
Professor Anthony Thomas, a physics professor at the University of Adelaide, explains, “Dark matter makes up as much as 84% of the matter in the universe, yet we know very little about it.”
“The existence of dark matter has been firmly established through its gravitational interactions, but its exact nature remains not fully understood despite the best efforts of physicists worldwide.”
“The key to understanding this mystery may lie in the dark photon, a theoretically massive particle that could act as a gateway between the dark realm of particles and regular matter.”
Dark Photon and its Significance
Regular matter, which we and our material world are composed of, is far less abundant than dark matter: dark matter exists many times more than regular matter. Gaining more knowledge about dark matter is one of the biggest challenges for physicists worldwide.
Dark photon is a hypothetical hidden-sector particle, proposed to carry a force similar to electromagnetic photons but with the capability to interact with dark matter. Testing the current theories about dark matter is one of the approaches that scientists like Professor Thomas, along with colleagues Professor Martin White, Dr. Xuangong Wang, and Nicholas Hunt-Smith, members of the Australian Research Council’s (ARC) Center of Excellence, are undertaking. Particle physics of dark matter seeks additional clues about this elusive but highly significant substance.
Some hypotheses suggest that, in addition to gravity, dark matter particles may interact with visible matter through a new force that science has not yet been able to detect. Similar to the electromagnetic force caused by photons, this dark force is believed to propagate through a type of particle called “dark photons” – intermediaries between visible matter and dark matter. These “dark photons” can interact with regular photons in a process called mixing, creating subtle but measurable effects.
Profound Insights from Particle Collision Events
Professor Thomas states, “In our latest research, we examined the potential effects that a dark photon could have on a comprehensive set of deep inelastic scattering experimental results.”
Analyzing the secondary products of particle collisions accelerated to extremely high energies provides scientists with valuable evidence about the subatomic world’s structure and the natural laws governing it.
In particle physics, deep inelastic scattering is the term used for a process used to probe the inner workings of hadrons (especially baryons like protons and neutrons) using electrons, muons, and neutrinos.
Professor Thomas explains, “We used the advanced global analysis framework of the Jefferson Lab Angular Momentum (JAM) Collaboration, modifying fundamental theory to allow for the existence of a dark photon.”
“Our work indicates that the dark photon hypothesis is preferred over the standard model hypothesis at a significance level of 6.5 sigma, constituting evidence for a particle discovery.”
The research team, consisting of scientists from the University of Adelaide and colleagues at the Jefferson Lab in Virginia, USA, has published their findings in the Journal of High Energy Physics.
The energy of these photons is measured and must be equivalent to that of electrons. However, if dark photons exist, they will carry a portion of the original electron’s energy, which detectors would pick up. Discovering any “dark photons” marks a significant breakthrough in the quest for dark matter – a hunt that has often yielded no results despite decades of efforts in the field of physics.