A global team of scientists has deepened our understanding of the complex nature of dark matter, which makes up 84% of the matter in the universe. They focused on the “dark photon,” a theoretical particle that could bridge the gap between the elusive dark sector and ordinary matter.
New knowledge about dark matter emerges as researchers explore ‘dark matter’ photon‘, calling into question the assumption of the Standard Model.
Led by experts from the University of Adelaide, a team of international researchers have discovered further clues in their quest to better understand the nature of dark matter.
“Dark matter makes up 84% of the matter in the universe, but we know very little about it,” said Professor Anthony Thomas, senior lecturer in physics at the University of Adelaide.
“The existence of dark matter has been firmly established based on its gravitational interactions, but its precise nature continues to elude us despite the efforts of physicists around the world.”
“The key to understanding this mystery may lie in the dark photon, a theoretical massive particle that could serve as a portal between the dark sector of particles and ordinary matter.”
“Our work shows that the dark photon hypothesis is preferred over the Standard Model hypothesis with a significance of 6.5 sigma, providing evidence for particle discovery.” — Professor Anthony Thomas
The dark photon and its meaning
Ordinary matter, of which we and our physical world are made, is much less abundant than dark matter: there is five times more dark matter than ordinary matter. Learning more about dark matter is one of the biggest challenges for physicists around the world.
The dark photon is a hypothetical hidden sector particle, proposed to carry a force similar to the photon of electromagnetism but potentially connected to dark matter. Testing existing theories about dark matter is one of the approaches taken by scientists such as Professor Thomas, along with their colleagues Professor Martin White, Dr Xuangong Wang and Nicholas Hunt-Smith, members of the Center of Excellence from the Australian Research Council (ARC). Dark matter particle physics continues in order to obtain more clues about this elusive but very important substance.
Particle Collisions Overview
“In our latest study, we examine the potential effects that a dark photon could have on the overall experimental results of the deeply inelastic scattering process,” Professor Thomas said.
Analyzing the byproducts of particle collisions accelerated to extremely high energies provides scientists with good evidence of the structure of the subatomic world and the laws of nature that govern it.
In particle physics, deep inelastic scattering is the name given to a process used to probe the interior of hadrons (especially baryons, such as protons and neutrons), using electrons, muons and of neutrinos.
“We used the Jefferson Lab Angular Momentum (JAM) state-of-the-art parton distribution function global analysis framework, modifying the underlying theory to account for the possibility of a dark photon,” said the Professor Thomas.
“Our work shows that the dark photon hypothesis is preferred over the Standard Model hypothesis with a significance of 6.5 sigma, providing evidence for particle discovery.”
The team, which includes scientists from the University of Adelaide and colleagues from the Jefferson Laboratory in Virginia, US, published their findings in the Journal of High Energy Physics.
Reference: “Global QCD Analysis and Dark Photons” by NT Hunt-Smith, W. Melnitchouk, N. Sato, AW Thomas, XG Wang and MJ White on behalf of the Jefferson Lab Angular Momentum (JAM) collaboration, September 15, 2023, Journal of High Energy Physics.
DOI: 10.1007/JHEP09(2023)096
