Hypothetical particles are proposed physical entities that extend or modify established particle content in a given theoretical framework, typically introduced to resolve inconsistencies, explain unexplained phenomena, or complete symmetries in high-energy and gravitational physics. As physical systems, they are characterized by well-defined quantum numbers, interaction types, mass scales, and roles in Lagrangian formulations, yet they lack direct experimental confirmation. Examples in model-building include particles postulated in supersymmetry, grand unified theories, dark matter and dark energy models, and quantum gravity scenarios, where their properties are constrained by consistency with known symmetries, renormalizability, cosmological evolution, and precision tests of the Standard Model and general relativity.
Dark matter could be a type of matter in the universe that does not emit, absorb or reflect detectable light and appears to interact very weakly with regular matter. Although physicists have observed gravitational effects ...
Researchers at the DarkSide collaboration have unveiled results from a seven-year experiment that tested whether dark matter particles could exist as composites of smaller, elementary particles. While the search turned up ...
Rice University researchers have used a magnetically levitated particle to search for ultraheavy dark matter, extending the hunt for some of the heaviest possible forms of the invisible matter thought to hold galaxies together. ...
General Physics
Sep 5, 2026
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An unexplained signal detected by the world's most sensitive dark matter experiment could mark a major breakthrough in the hunt for the elusive substance, according to an analysis involving scientists from the University ...
General Physics
Sep 1, 2026
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Astronomers can't see dark matter directly, but they know it's there: Its gravity shapes galaxies and the large-scale structure of the cosmos. In an effort to uncover the composition of this hidden mass, a team at Lawrence ...
General Physics
Aug 25, 2026
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Theoretical physicists have long predicted the existence of millicharged particles (mCPs), hypothetical particles that carry a very small electric charge. These particles are expected to interact very weakly with ordinary ...
Composing some 85% of the universe's total mass, dark matter betrays its presence only through gravity, unlike ordinary matter. Yet through new research published in Physical Review D, a team led by David Dunsky of New York ...
Using a detector filled with nearly 9 metric tons of liquid xenon, researchers have delivered some of the most sensitive dark matter results ever recorded. In the latest analysis from the XENON collaboration, working at the ...
Dark matter's existence is all but certain—astronomers believe it makes up about a quarter of the universe's total energy content—yet its true identity has eluded us for decades. Two of the leading candidates for dark matter ...
General Physics
Aug 5, 2026
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For decades, a theory in physics has postulated the existence of a mirror world whose interaction with our own reality is extremely feeble. The particles in this mirror universe are also thought to be candidates for dark ...
General Physics
Jul 28, 2026
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