New discoveries in the realm of dark matter have come to light as researchers delve into the intriguing ‘dark photon’ hypothesis, challenging the conventional standard model. A group of international researchers, under the leadership of experts from the University of Adelaide, has unearthed fresh insights in their relentless pursuit of understanding the enigmatic nature of dark matter.
Professor Anthony Thomas, the Elder Professor of Physics at the University of Adelaide, expressed, “Dark matter constitutes a staggering 84 percent of the matter in the universe, yet our knowledge of it remains profoundly limited. While we have firmly established its existence through gravitational interactions, the precise identity of dark matter continues to elude us, despite the collective efforts of physicists worldwide.”
“The key to unraveling this enigma may lie with the concept of the dark photon, a theoretical massive particle that could potentially serve as a bridge between the shadowy realm of dark particles and conventional matter.”
“Our research demonstrates that the dark photon hypothesis exhibits a preference over the standard model hypothesis at a remarkable significance level of 6.5 sigma, constituting compelling evidence for the discovery of a new particle,” concluded Professor Anthony Thomas.
The Dark Photon and Its Implications
Dark matter, which dwarfs regular matter in abundance, with five times more dark matter than its ordinary counterpart, represents one of the foremost challenges confronting physicists globally. The dark photon, a speculative particle within the hidden sector, is posited as a force carrier akin to the photon of electromagnetism, but potentially linked to the mysterious dark matter. Scientists like Professor Thomas, in collaboration with colleagues such as Professor Martin White, Dr. Xuangong Wang, and Nicholas Hunt-Smith, all members of the Australian Research Council (ARC) Centre of Excellence for Dark Matter Particle Physics, are actively pursuing various avenues, including the examination of existing dark matter theories, to glean further insights into this elusive yet profoundly consequential substance.
Revelations from Particle Collisions
“In our latest investigation, we scrutinize the potential ramifications of the dark photon on the complete dataset stemming from deep inelastic scattering processes,” elucidated Professor Thomas.
The scrutiny of by-products emanating from high-energy particle collisions furnishes scientists with compelling evidence pertaining to the subatomic realm and the governing laws of nature. Within particle physics, deep inelastic scattering refers to the process employed to probe the inner workings of hadrons, particularly baryons like protons and neutrons, using particles such as electrons, muons, and neutrinos.
“We have harnessed the cutting-edge Jefferson Lab Angular Momentum (JAM) parton distribution function global analysis framework, incorporating adjustments to the underlying theory to accommodate the possibility of a dark photon,” Professor Thomas explained.
“Our research conclusively demonstrates that the dark photon hypothesis enjoys a preference over the standard model hypothesis, with a significance level of 6.5 sigma, thus constituting persuasive evidence for the existence of a new particle.”
The research team, comprised of scientists from the University of Adelaide and collaborators at the Jefferson Laboratory in Virginia, USA, has disseminated its findings in the Journal of High Energy Physics.
Reference: “Global QCD analysis and dark photons” by N. T. Hunt-Smith, W. Melnitchouk, N. Sato, A. W. Thomas, X. G. Wang, and M. J. White on behalf of the Jefferson Lab Angular Momentum (JAM) collaboration, published on 15th September 2023 in the Journal of High Energy Physics.