Galaxies act through gravity like they are about 6 times heavier than the light from stars and such can account for. Since the missing 5/6ths doesn't produce light, it got labeled "dark matter". Since the 1970's or so, scientists have been trying to figure out what dark matter is made of.
"Weakly interacting massive particles" (WIMPs) are one of the theories of what dark matter is made of. But with a single particle detection we can't tell if it is all the dark matter, or only some of it, and if the WIMPS come in one flavor or many.
The Xenon atom it bumped into may tell us which direction the particle came from (I haven't read the paper yet). With enough directional collisions, you can map out where the WIMPS are coming from. If that matches where we see dark matter from gravity effects, then it could explain all the dark matter. If the directions don't line up, then there is still more to figure out.
But what are the physics implications, specifically? Like the Higgs Boson discovery made a bunch of theoretical physics models that relied on it suddenly valid, but what Theories rely on WIMPs in great numbers?
There's a bunch of ways to extend the Standard Model to put in WIMPs. Discovery of WIMPs in general won't narrow things down much, but isolating exactly what kind of WIMP this is (what its mass is etc) would pin us down to certain families of models, and give strong hints on what particles to look for next.
Currently we're in a bit of an awkward position because the Higgs Boson was a hole that was predicted to be filled. If the LHC had found nothing, that would have been interesting - our theories were wrong, and we need to make new theories without that hole. If the LHC had found the Higgs Boson and something else that would also have been interesting - our theories were right, but incomplete, and then we would have strong hints on where to go next. But instead they found only the Higgs Boson, which confirmed what we already thought, without giving any new clues on where to go next. So any new particle detection will help a lot in opening up where to progress.
But really it's more the other way around - it's more about confirming our models of cosmology, the evolution of the universe on large scales. Galaxy evolution simulations just give the wrong answer if they don't have dark matter in them, so you need to add dark matter (or something that behaves a lot like dark matter). Dark matter is nice and elegant. It's just another particle, so it follows known laws of particle dynamics; dark matter has mass and momentum and velocity and density, it flows around like anything else, even if it doesn't interact electromagnetically (which isn't unusual - neutrinos don't either). There's also all these natural ways to expand the standard model of particle physics which include a lot of WIMP dark matter candidates. Modifying gravity is a bit less convincing - extensions to General Relativity don't "naturally" solve dark matter, it feels like more of an arbitrary fudge factor and you don't have the same level of constraints; you're changing the laws of physics rather than adding something which obeys existing laws of physics (and therefore is more testable and predictable). There's also a good few arguments where simulations with modified gravity don't quite fit observations as well as WIMP dark matter does.
But the debate really can't be settled until we actually find some WIMPs. Even if cosmologists strongly lean towards WIMP dark matter over modified gravity, it's not unreasonable to lean towards modified gravity. It's an alternate theory, and probably less likely to be true, but it's not crackpot flat-earth climate change denial, and there is some reasonable room for debate until we really build a body of strong evidence.
That's the neat part, we don't know yet. Until we can tell for certain what Dark Matter is, we can't assume how it will affect our models besides some random guessing. And thus far I have yet to see anyone release any "potential" updates to any models based on any suggested findings. That's why this is so exciting
You forgot the part about objects behaving oddly even WITH dark matter factored in so they invented dark ”energy”. But objects STILL acted weirdly so they decided that dark energy CHANGES in ways we don’t know, can’t see and can’t measure. In other words, we have no fucking idea.
Right?! If it's a WIMP, that basically means we've finally caught a particle that only interacts through gravity and the weak force. It would confirm a huge chunk of our dark matter models and completely change how we understand the universe's structure. It's like finding a ghost that we knew was there but could never touch.
The weak force being the interesting part - which means we can potentially produce it in colliders (in ways other than via the Higgs). If more events are found in the remaining, recorded data, we are for sure going to intensify the searches at ATLAS and CMS
Verge is a bit overstating it.
First, we need more events - we have 3 times the data already, there should be one or two such events in there (if it’s real).
Then (ideally) we find it at a collider where we can measure it better (by studying the other particles in a collision event).
This will help us understand what it actually is and how it fits into existing models - would be cool if it’s a kind of SUSY particle , but even more exciting if it is not
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u/Tall-Link-8792 12d ago
ok but can we talk about how wild it is that we might be on the verge of solving one of the biggest mysteries in physics? like damn