The key to understanding the mystery of elusive dark matter could lie with the dark photon, a hypothetical dark sector particle proposed as a force carrier similar to the photon of electromagnetism.
Dark photons are hypothetical dark sector particles. Image credit: University of Adelaide.
“Dark matter makes up 84% of the matter in the Universe but we know very little about it,” said University of Adelaide’s Professor Anthony Thomas, co-author of a paper published in the Journal of High Energy Physics.
“The existence of dark matter has been firmly established from its gravitational interactions, yet its precise nature continues to elude us despite the best efforts of physicists around the world.”
“The key to understanding this mystery could lie with the dark photon, a theoretical massive particle that may serve as a portal between the dark sector of particles and regular matter.”
Regular matter, of which we and our physical world are made up of, is far less abundant than dark matter: five times more dark matter exists than regular matter.
Finding out more about dark matter is one of the greatest challenges for physicists around the world.
The dark photon is a hypothetical hidden sector particle, proposed as a force carrier similar to the photon of electromagnetism but potentially connected to dark matter.
Testing existing theories about dark matter is one of the approaches that Professor Thomas and his colleagues from the Jefferson Lab Angular Momentum (JAM) Collaboration are pursuing in order to gain more clues into this elusive but highly important substance.
“In our latest study, we examine the potential effects that a dark photon could have on the complete set of experimental results from the deep inelastic scattering process,” Professor Thomas said.
Analysis of the by-products of the collisions of particles accelerated to extremely high energies gives scientists good evidence of the structure of the subatomic world and the laws of nature governing it.
In particle physics, deep inelastic scattering is the name given to a process used to probe the insides of hadrons (particularly the baryons, such as protons and neutrons), using electrons, muons and neutrinos.
“We have made use of the state-of-the-art JAM parton distribution function global analysis framework, modifying the underlying theory to allow for the possibility of a dark photon,” Professor Thomas said.
“Our work shows that the dark photon hypothesis is preferred over the Standard Model hypothesis at a significance of 6.5 sigma, which constitutes evidence for a particle discovery.”
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N.T. Hunt-Smith et al. Global QCD analysis and dark photons. Journal of High Energy Physics 2023 (096); doi: 10.1007/JHEP09(2023)096
