Record-Setting Dark Matter Detector Comes Up Empty -- and That's Good News (gizmodo.com)
- Reference: 0178314854
- News link: https://science.slashdot.org/story/25/07/08/2255240/record-setting-dark-matter-detector-comes-up-empty----and-thats-good-news
- Source link: https://gizmodo.com/record-setting-dark-matter-detector-comes-up-empty-and-thats-good-news-2000625783
> WIMPs (weakly interacting massive particles) are one of the most serious contenders for dark matter -- the "missing" mass supposedly constituting 85% of our universe. Given its elusiveness, dark matter tests the patience and creativity of physicists. But the latest results from LUX-ZEPLIN (LZ), the South Dakota-based detector, [1]may have brought scientists a small step closer to catching WIMPs in action . In a recent [2]Physical Review Letters paper , scientists analyzed 280 days' worth of data from LUX-ZEPLIN, reporting the tightest ever upper limit on the interaction strength of WIMPs. The result -- a near fivefold improvement -- demonstrates how physicists are increasingly getting better at circumventing the problem that dark matter is, well, dark; the elusive stuff evades any detection method that depends on materials interacting with visible light or other types of radiation.
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> The [3]LUX-ZEPLIN experiment , located one mile underground in a decommissioned South Dakota gold mine, employs nearly 15,000 pounds (7 tons) of liquid xenon. The chemical element's high atomic mass and density make it potentially easier for scientists to detect any unknown particles that may pass through the detector. Also, liquid xenon is transparent, preventing any unwanted noise -- usually arising from radioactive matter around the detector -- from spoiling an experiment. "These results firmly establish that LZ is the world's most sensitive search for dark matter heavier than 10 GeV, that's about 10 times heavier than a proton," explained Scott Haselschwart, a physicist at the University of Michigan and LZ physics coordinator, in an email to Gizmodo. "To put our result in perspective: we have ruled out dark matter that would interact only once in a single kilogram of xenon every four millennia!"
"LZ is the most sensitive search for WIMP dark matter to date, but we still have another two years of data to collect," Haselschwart said. "This means that a discovery of dark matter in LZ could come anytime now. We are truly looking for dark matter where no one has ever looked before and that is extremely exciting!"
[1] https://gizmodo.com/record-setting-dark-matter-detector-comes-up-empty-and-thats-good-news-2000625783
[2] https://journals.aps.org/prl/abstract/10.1103/4dyc-z8zf
[3] https://lz.lbl.gov/
"where no one has ever looked before" (Score:2)
> We are truly looking for dark matter where no one has ever looked before and that is extremely exciting!
Did they check between the sofa cushions? That's one of the places I always look for stuff I can't find. The stuff always ends up being in the last place I look, though.
Re: (Score:1)
"Dark matter" is about to go the way of phlogiston and luminiferous aether.
Re: (Score:2)
On the dark side of the moon there is a pile of single socks filled with dark matter.
Re: (Score:2)
>> We are truly looking for dark matter where no one has ever looked before and that is extremely exciting!
> Did they check between the sofa cushions? That's one of the places I always look for stuff I can't find. The stuff always ends up being in the last place I look, though.
Dude, the number of times I've found things that fell *through* the couch to the floor when I move the couch years later.... Maybe they should check under the recliner too, while they're at it.
Ain't none (Score:3)
Dark matter is a kludge. Something is off in our models, or we're missing something else. So we invent ether invisible, undetectable "dark matter" to explain the discrepancy.
Agreed (Score:2)
Just like newtonian mechanics couldn't explain the orbit of mercury without a load of kludges and then relativity came along and solved it. I suspect we need a whole new branch of physics to find the true answer.
Another Nail In Supersymmetry's Coffin (Score:1)
Just like the subject says, supersymmetry, an elegant solution to a number of problems, in particular the best theoretical extension to the Standard Model, slides closer to oblivion with each large scale and small scale (accelerator) experiment meant to find these large supersymmetrical particles.
Searching underground? (Score:2)
Wouldn't any theoretical dark matter have collided (or simply interacted) with all that rocky mass above and, well, not be present in a cave?
This is like searching an empty barrel to prove that fish exist in the pond.
-why yes, I like to oversimplify overly complex theories that keep wasting someone else's money that I don't care about.
This has been going on for 100 years (Score:3, Interesting)
!5 Years or so ago the Planck experiment ruled out most of the preferred inflationary models -GREAT SUCCESS- -NOTHING TO SEE HERE- Now this experiment rules out the most likely candidate for dark matter -GREAT SUCCES- -NOTHING TO SEE HERE- There is no evidence for the Lamgda Cold Fusion Model other than the inability of scientist to predict the motion of stars. Billions and Billions of dollars and 100 years have shown that this theory is wrong. Time to move on.
Re: (Score:3)
The "Time to move on" call is all nifty and fine.
The problem is: Where to?
We have no obvious path, and the ones proposed so far are even more elusive. Physicists would love to move on, and the ones leading a promising new way will be hailed as the Newtons and Einsteins of the 21st century. Currently, we are in the process to mark out all possible places to look, and we are crossing out the squares we have searched so far. Each square cleared is a success, because it narrows down the places to look even
Re: (Score:2)
The Minesweeper strategy is no way to do science, or is it? What happens if you clear all the squares only to find nothing? Do we just start over?
-Yes that is many questions, but it is better than ruling just on thing out each decade, is the current pace even that fast? Oops another question - we just don't have any answers. It's OK to admit this.
Re: (Score:2)
The Minesweeper strategy is in fact the only way to do Science. Each theory in Science can be formulated as a negative, as events ruled out by the theory. That's how falsification works. If something happens which has been ruled out by the theory, then the theory has a flaw.
Alternative Models (Score:2)
> We have no obvious path, and the ones proposed so far are even more elusive.
That's not really true. Axions - that solve the strong CP problem - are looking like an increasingly likely candidate for Dark Matter. LIGO can also test the hypothesis that Dark Matter is just small Black Holes - while the source of such BHs is not theoretically motivated it's not experimentally ruled out yet and if they were found we all know the theorists would come up with ideas of where they came from!
While you could argue that none of these are "obvious paths" with the death of the WIMP miracle I
Michelson-Morley (Score:2)
True, but 100+ years ago when the Michelson-Morley experiment did not find any evidence of the aether that was supposedly the medium that transmitted light, it helped to completely reshape our way of understanding physics since it directly led to the discovery of relativity.
Negative results can sometimes be very profound...although for LUX that is not really the case. I would not describe this result as exciting but it is useful. To be exciting they would actually have to have found evidence of Dark Matt
Re: (Score:2)
The problem is that we don't have a better theory than dark matter to explain the motion of galaxies, although MOND and its derivatives are a close second.
A good theory must explain all observations with the least amount of free parameters. And dark matter is actually quite good in that regard: we have stuff that is massive and that we currently can't detect except for its gravitational effect on galaxies, and a particle is currently the favorite candidate. I mean, why not, neutrinos were like that not so l