Weakly Interacting Massive Particles (WIMPs)
Context:
The search for Dark Matter remains one of the biggest unresolved mysteries in physics.
While WIMPs have long been the leading candidate to explain dark matter, experiments have not yet detected them, pushing researchers to consider alternatives like axions or modified gravity theories.
About Dark Matter:
Dark matter is a form of matter that does not emit, absorb, or reflect light, so it cannot be seen directly.
Its existence is confirmed through gravitational effects on galaxies, galaxy clusters, and cosmic structures.
Dark matter makes up about 27% of the universe's mass and energy, whereas visible matter (stars, planets, gas) accounts for only about 5%.
It is invisible, meaning it does not emit, absorb, or reflect light, making it undetectable by traditional electromagnetic telescopes.
Thus Dark matter is:
electrically neutral
Does not interact with light (photons)
Does not lose energy or form atoms, stars, or galaxies
Role of WIMPs:
WIMPs have historically been the primary theoretical candidate for dark matter.
As the name suggests, these are massive particles (relative to other particles like axions) that interact very weakly with ordinary matter.
Key Characteristics of WIMPs
Much heavier than normal particles like electrons
Interact with normal matter only through gravity and weak nuclear force.
Neutral: No electric charge
Invisible: Do not emit light
WIMPs are not one single particle, but a class of hypothetical particles.
Other WIMP’s includes Axioms, Neutrinos.
Neutralino is one of the strongest WIMP candidates for dark matter.
A neutralino is a hypothetical particle predicted by Supersymmetry (SUSY), an extension of the Standard Model of particle physics.
Despite being easier to detect theoretically than lighter alternatives, they have not yet turned up in experiments.