LZ Experiment Sees Surprising Result In Search For Dark Matter (brown.edu) 29
New submitter greytree shares a report from Brown University: LUX-ZEPLIN, an experiment co-led by Brown University faculty and students, observed a particle interaction that could be interpreted as a signal from WIMPs, a dark matter candidate -- but researchers need more data to confirm. [...] The result does not yet meet the statistical threshold required to claim a discovery, but it is the most compelling hint of dark matter reported by the experiment to date. "We're very intrigued to see this event in the data, in the region where we expect dark matter to show up, and the competing backgrounds are very low," said Rick Gaitskell, a professor of physics at Brown University and the spokesperson for LZ. "With only one event, we don't want to get ahead of ourselves. We are not claiming to have seen dark matter. But we have seen something interesting that we want to share with the scientific community for their input." [...]
If the anomalous event was caused by dark matter, the WIMP that generated it would likely have a mass of at least 200 GeV/c2 (gigaelectronvolts), or more than 200 times the mass of a proton. The LZ results have not reached "5-sigma" significance, the statistical threshold in physics that an event must reach to be considered a discovery. The new analysis is 2.6 sigma, meaning there is approximately a 0.5% chance that the event could be explained by known backgrounds. With additional data, researchers can test whether the finding continues to grow in significance or fades away. LZ has already accumulated the world's largest dark matter dataset and will continue to accrue WIMP search data at SURF, substantially improving their search statistics.
JiJi Fan, an associate professor of physics at Brown not involved in the LZ experimental research but whose theoretical work is cited in the new LZ paper, said the new findings were "very intriguing." While the event recorded by LZ could not have been the simplest type of WIMP interaction, there are other types of possible interactions that could explain it, she said. Had a WIMP interacted in the simplest way at the high energy associated with this recent event, the detector would have recorded many recoil events at lower energies following the initial event. LZ recorded a single event, however, which requires an expanded theoretical explanation. "There are well-motivated theoretical extensions, including inelastic scattering and momentum-dependent elastic scattering, that could potentially account for this single event," Fan said. "This also sets up a target for on-going dark matter hunting, not only at direct detection experiments such as LZ but also at other complementary experimental frontiers." The results were presented in a scientific talk at the 2026 TeV Particle Astrophysics conference in Japan on Tuesday, Sept. 1. A paper detailing the finding can be found here (PDF).
If the anomalous event was caused by dark matter, the WIMP that generated it would likely have a mass of at least 200 GeV/c2 (gigaelectronvolts), or more than 200 times the mass of a proton. The LZ results have not reached "5-sigma" significance, the statistical threshold in physics that an event must reach to be considered a discovery. The new analysis is 2.6 sigma, meaning there is approximately a 0.5% chance that the event could be explained by known backgrounds. With additional data, researchers can test whether the finding continues to grow in significance or fades away. LZ has already accumulated the world's largest dark matter dataset and will continue to accrue WIMP search data at SURF, substantially improving their search statistics.
JiJi Fan, an associate professor of physics at Brown not involved in the LZ experimental research but whose theoretical work is cited in the new LZ paper, said the new findings were "very intriguing." While the event recorded by LZ could not have been the simplest type of WIMP interaction, there are other types of possible interactions that could explain it, she said. Had a WIMP interacted in the simplest way at the high energy associated with this recent event, the detector would have recorded many recoil events at lower energies following the initial event. LZ recorded a single event, however, which requires an expanded theoretical explanation. "There are well-motivated theoretical extensions, including inelastic scattering and momentum-dependent elastic scattering, that could potentially account for this single event," Fan said. "This also sets up a target for on-going dark matter hunting, not only at direct detection experiments such as LZ but also at other complementary experimental frontiers." The results were presented in a scientific talk at the 2026 TeV Particle Astrophysics conference in Japan on Tuesday, Sept. 1. A paper detailing the finding can be found here (PDF).
Derivation of the Radial Acceleration Relation (Score:5, Interesting)
The RAR equation is an empirical equation based on 100+ galaxies data. No derivation of the equation exists.
I have an elastic vacuum model from which I derived the exact equation. The interpretation is that RAR (and MOND) describers the transient
region how cosmic expansion recovers from H=0 inside the galaxy to full H=H0. Within the elastic vacuum model the RAR equation is a prediction.
You can read the Postulates and you can jump right into chapter 9 and read also the Appendinx. You do not have to concern yourself with the GR stuff in the document.
At this point, I see 3 options.
1. The derivation is false and I use totally wrong math
2. I am extremely lucky to get this out of the vacuum model and it is just a weird coincidence
3. Maybe there is something here and treating the vacuum as a real material may have some merit.
https://www.researchgate.net/p... [researchgate.net]
If any physicist read this, feel free to contact me and point out any errors and/or inconsistencies concerning the derivation or other topics in the document.
Re:Derivation of the Radial Acceleration Relation (Score:4, Funny)
Re: (Score:2)
I know what .rar and .gz are. If .lz is something similar, maybe dark matter is a compression artifact.
Re: (Score:2)
Except they're all lossless compression so no artifacts
Re: (Score:2)
Re: (Score:2)
At this point, I see 3 options. 1. The derivation is false and I use totally wrong math
At least both Claude Fable 5.1 and ChatGPT 5.6 "Terra" say it is option 1. Their analysis would be too long and too full of symbols not reproducible in Slashdot ASCII, but here are just some section headlines of what they complain:
## 1. The static field equation conflicts with the proposed Schwarzschild spacing profile ## 3. The “elasticity” argument confuses displacement and strain ## 4. The time-dilation postulate changes between equations ## 5. The moving-field solution is not obtained merely by Lorentz-transforming a scalar static solution ## 6. Constant-speed circular motion is incorrectly treated as involving no state update ## 7. The frame-dragging derivation gets only a dimensional falloff, not the effect ## 8. The gravitational-wave calculation imports GR rather than derives it ## 9. The RAR “derivation” is mathematically unsupported ### The “deep-MOND amplitude” is an algebraic identity, not a dynamical derivation ### The obstacle-problem substitution is invalid ## 11. The dark-energy section contains a direct algebraic contradiction 1. Eq. (14) and Eq. (16) are incompatible outside matter. 2. Eq. (16) makes the proposed force diverge at the horizon. 3. The time-dilation rule changes between Eqs. (36) and (37). 4. The RAR derivation relies on an unjustified replacement of \(s/\ell\) by \(k/k_*\). 5. The dark-energy section has a direct error: \(\delta\to1\) implies \(w\to0\), not \(-1/3\). 6. Several results claimed as derivations are instead obtained by importing GR equations or selecting relations that reproduce the desired empirical result.
Re: (Score:2)
Thank you checking the document with the highest models. I do not use those since I would run out of credits very quickly.
Can you send the full analysis to my email address which is in the document? It seems most of the complaints concern the GR stuff which is expected. But the RAR derivation does not really connect to that. Appendix A gives a mathematical explanation using wavenumbers and 3 different AI models (not the highest) agreed it is correct. What does Fable say about Appendix A?
Anyway, let's take t
Re: (Score:2)
Re: (Score:2)
Thank you very much. I already did some fixes with Opus 5. RAR survided and it is actually better. Wavenumbers are not needed. Gravity and Black Holes are also much better.
I know its not an original idea (Score:2)
But I still find it fascinating that there may be a whole dark matter universe amongst us that we dont know about with maybe structure and even life? Perhaps theres some dark matter professor right now trying to figure out what that missing 20% of the universes mass is made of.
Re: (Score:1)
Some boffin cam up with that idea, but they rule it out because DM apparently doesn't interact with itself (very much) other than by gravity, so it can't clump up tight like a star or a planet or a living thing. (Something to do with shedding energy, IIRC.)
But it's a cool idea. If I were a novelist I'd run with it.
Re: (Score:2)
To be frank, if they don't know what it even is I fail to see how they can have any idea about how it interacts with its itself or what any of physical properties are other than gravitational. And maybe dark energy is the dark matter universe version of electromagnetism.
Re: (Score:2)
The fact that it makes a big cloud around a galaxy or cluster rather than collapsing puts a lot of constraints on what it can do.
For more info, you'll have to go to someone who knows more about it than what I've read on science-news websites.
Dark energy is a real puzzle. As I understand it, it's too weak by a factor of 10^30 or 10^60 in comparison from what we should expect the known vacuum energy would cause. You see this mentioned very occasionally, but most treatments of DE that a layman runs across ju
Re:I know its not an original idea (Score:4, Informative)
And they can rule out interaction of Dark Matter with itself on a large scale of magnitudes, e.g. everything above the Weak Force.
Re: (Score:2)
How would you see the effects of it if it barely interacts with matter or energy other than gravitationally? It could respond to a number of forces that have no equivalent in the ones we currently know of. The standard model is incomplete ergo it cannot by definition rule out things not in it.
Re:I know its not an original idea (Score:4, Informative)
Re: (Score:2)
Huh? If dark matter doesn't react in any way with electromagnetic radiation it will have zero effect on the background temperature.
Re:I know its not an original idea (Score:4, Interesting)
Second order effects. The following is wrong and grossly oversimplified but gives some idea of how it works.
The 2.7K Cosmic Microwave Background (CMB) is understood to be red-shifted thermal emissions from a 3000K H/He plasma from when the universe was very young. The red shift is caused by the expansion of the universe. Dark matter can cause small variations in either the temperature or polarization of those thermal emissions by gravitationally making the plasma denser (and hotter) or less dense (and cooler). Detailed measurements of the CMB is what has really motivated most of the dark matter / dark energy picture.
Re: I know its not an original idea (Score:2)
I imagine number of things could have caused tiny variations and in fact probably theory states that a perfectly even mixture is far less likely than an uneven one due to random variation.
Re: (Score:2)
Re: (Score:3)
Re: (Score:2)
Essentially there appears to be a hole in understanding. Whatever dark matter may be, if it exists, it must fit the hole.
Re: (Score:2)
There are so many unknowns in "dark matter" that they can't really claim it doesn't interact with itself. Some of the theories have it not interacting with itself, but that's not a good argument. There are too many possibilities. ...From here on I'm just spinning ideas...
FWIW, I came up with a theory that there are nine basic flavors of dark matter, each about 1/10th the mass of the universe, and the various flavors don't interact with each other, but they do interact with themselves, and are as varied wi
Re: (Score:2)
DM apparently doesn't interact with itself (very much)
So, like Gen Z. Order from DoorDash, work from home. And then there's that Gen Z stare.
JiJi Fan and the SURF WIMPs (Score:3)
JiJi Fan and the Surf Wimps used to be my favorite band. Some say that they stopped performing because they just ran out of energy, but the actual circumstances leading to their departure from the public eye are a dark matter indeed.
2.6 sigma = Yawn (Score:5, Interesting)