So it's certainly interesting!
That said, particle physics history is full of 3 sigma particle "discoveries" that disappeared with more data. They're collecting more, so hopefully we'll learn more in a few more years.
[1] https://lz.lbl.gov/wp-content/uploads/sites/6/2026/08/LZ_Pre...
would you include all the quoted text in the reply-alls, or is that too much?
Science has too many threads to do it successfully though
Only quote the relevant part and reply to it, just like this very comment.
And Linux has a large mailing archive of various lists and threads that are searchable and available to everyone and get this: free access
(Notwithstanding the absurdity of academic publishing, of course.)
https://www.scientificamerican.com/blog/information-culture/...
Which of course is the point: it is in fact quite similar to a mailing list, just with some extra protocol surounding it to make it manageable.
So the attempted snark about it up thread is stupid.
A paper has a (semi-formal) structure, including TITLE, AUTHORS, and the all-important ABSTRACT.
Email guarantees none of those.
Pre-prints are basically a mailinglist where you post your paper prior to peer review.
The value over a simple mailinglist is:
1. Stable URL and citation to enable other work and discussions to cite and reference it.
2. Versioning of the paper, allowing updates to be made without having mail out the paper, while allowing everyone to find all prior versions
3. Host for a PDF and data that might be quite large
4. Centralized searchable long term archive of scientific papers
5. Scalability, arxiv gets 30,000 submissions a day, no one wants to receive 30,000 PDFs in their inbox everyday
It was a fascinating experience as a junior member to follow the collaboration internal conversation and investigation on this, because a lot of extremely principled scientists were clearly deeply worried about losing their hard earned reputation. In the end, I am convinced that we were simply unlucky.
It's stories like this that raise my p(we are in a simulation).
Then when it comes out as measurement error, the public is all "Damn these scientists are all hype machine clowns..."
I’m less fine with the time and resources spent on mouse models. They already know you’d get the same utility from a magic 8 ball, but they do it anyway.
Also, you can do nasty stuff to mice that would never be allowed with humans. In that experiment they injected cancer cells in mice with a bad inmune system, so they could get like 90 mice with cancer and run the experiment in a short time. No ethical committee would approve that in humans.
Congratulations. You've just reduced all of medical science to the Tuskegee STD experiment.
I was a bit dismayed at the reaction within the physics community. Experiments absolutely do need to follow procedures like blinding and careful internal review (especially before the data unblinding), but you can only spend so long designing the analysis before you unblind, and there are opportunity costs to cross checking everything. In an optimized community experiments will inevitably make mistakes. And once you unblind, it does no one any good to sit on an anomalous result forever.
I think the final COVID consortium report has something like 30k authors.
The Pierre Auger Observatory certainly is a large collaboration for the astroparticle physics domain though. It's a big international collaboration.
Quick anecdote: my name (S Mueller) is not on that paper's author list because we had a rule that you had to be in the collaboration for a year before getting authorship. You stayed on for a year after leaving. Very reasonable! At the time I was nonetheless a bit bummed about missing out on the big Science paper. I guess I'm on the retraction though ;)
The idea is that because 3 sigma means a ~1/1000 chance of the thing being explained by random chance, 1 in 1000 experiments will produce a bogus 3 sigma result, and we do many thousands of experiments.
They were pretty model agnostic in what they were looking for. They modeled and simulated a number of different ways a WIMP could interact with normal matter. If this is a discovery, more data will be needed to figure out the nature of that interaction and how it fits into particle physics.
But there's always a chance it's something completely new, or some extremely rare manifestation of things we already know about, but have never seen before. And even if it is WIMP, it may not be the right type of WIMP (wrong mass, or wrong interaction strength) to explain cosmological dark matter.
When doing this kind of thing, the analysts will plot the rate of events as a function of "distance from the outer surface" and confirm that it decreases, and in this case "is 0" inside of the detector used for analysis.
But keep in mind that all statements are made statistically, so it's not that the event _can't_ be an external neutron, but that it is _very_ unlikely to be.
That's not to say it can't be a neutron, but it would be surprising if it were.
Culturally, an attempt to intentionally distort or misrepresent data to suggest a result like this would not be tolerated. You can imagine a bad actor writing a single-author paper with fakery, but a collaboration at this level is inherently critical of itself and everyone holds each other accountable.
But mistakes do happen. Exciting results or hints of exciting results can appear due to well-intentioned researchers making convenient mistakes which get glossed over for psychological reasons and then add up to appear as something significant. You can read about "blinding" (which is mentioned in the paper) to get a feel for the techniques researchers employ to not only guard against fabricating results intentionally, but even unintentionally.
The point of "blinding," as I mentioned it before, is to guard against biasing the result due to choices made by analysts while figuring out how to compute their final answer. Part of that is just psychological --- if an analyst _knows_ that the data is obscured, for lack of a better term, in a way such that they can't believe a signal that they see (for example --- that's just one way to blind), then they won't feel any emotion or excitement about things they encounter while constructing the analysis, because they know what they're looking at isn't real, and that helps them to maintain objectivity. It's also common to have multiple independent analysis teams for something like this --- they know that they'll have embarrassed themselves if they don't all get the same result both before and after unblinding, which provides pressure to maintain objectivity.
As far as review goes --- there are physicists who believe in dark matter, and there are physicists who don't believe in dark matter. But all particle physicists and nuclear physicists use the same core technical and statistical methods. For a result like this, there will be a few "core analysts" who do the analysis, typically graduate students and postdocs. Their advisors review their work, through the lens of making sure that they are doing so sanely. The collaboration will also establish an internal review committee to comb through the documentation and software which produced the result, not necessarily trying to disprove what they found, but really looking at it critically. Once it gets to a journal, they'll get reviewers who may be biased for or against the result, and who may or may not work directly on dark matter detection, but who can all assess the methodology by which the result was obtained. That's probably the best we can do with humans involved.
However, the context here is that the DOE has already paused funding for the experiment's successor, XLZD, for an unspecified amount of time which realistically, is probably going to depend on the next US presidential election. At the same time, the DOE encouraged the LZ project to develop scenarios for continuing to operating beyond its current end date of 2028.
Now, here's what the NBC Bay Area report I mentioned[0] ended with:
> "All the more reason, they say, to keep these machines running. [...] They'd like to keep the machines running, they wanna keep doing this research, they're applying for funding now, so fingers crossed, we'll have more updates on this [...]"
The media attention this received was not the organic result of some journalist noticing the preprint or the talk at TeVPA in Japan. There was a major wave of synchronized official press releases, coinciding with the TeVPA talk, from Berkeley National Lab[1], Brown University[2], SLAC[3], Brookhaven[4], Stanford[5], University of Sydney[6], and others including UMass Amherst and Imperial College London.
Now, these institutions are all involved in the collaboration somehow, so it makes sense that they would coordinate press releases for a major result. The question is whether this result warrants such treatment. It's a single event at 2.6 sigma global significance. Promoting it in this way was a choice, and I'm pointing out that it seems quite possible - in fact I'd say extremely likely - that that choice was made with the funding situation top of mind.
[0] https://www.youtube.com/watch?v=bf3aW0xTEEc
[1] https://newscenter.lbl.gov/2026/09/01/lz-sees-surprising-res...
[2] https://www.brown.edu/news/2026-09-01/lz-dark-matter-results
[3] https://www6.slac.stanford.edu/news/2026-09-01-lz-sees-surpr...
[4] https://www.bnl.gov/newsroom/news.php?a=123133
[5] https://news.stanford.edu/stories/2026/09/dark-matter-detect...
[6] https://www.sydney.edu.au/news-opinion/news/2026/09/03/lz-ex...
But I don't see anything particularly strange or coordinated is happening. From the collaboration's perspective, it's quite stressful having this event. They've already unblinded, so it would be unethical to do anything other than report what they found. If they publicize it and it's a mistake, then that's a big blow to their credibility. But if they withhold it and it's real, then they miss making the discovery and/or bias their future analyses on larger datasets without disclosing that to the community. So they are in a tough spot, and are safest to just tell the world what they saw.
This is getting media attention because it would be a big deal to the general public if this ends up being a real. Someone in the field wouldn't claim that it's real, but the possibility is catnip to folks looking for a sensational headline. That the press releases are synchronized in time is because the result was just released right now and they're all doing their commentaries right away --- for something like this, each institution independently negotiates a release with the local researchers who are involved. They all promise to wait until the result is officially released, out of respect for the scientific process, like you say, but the different institutions aren't coordinating with each other. They're just all respecting their own researchers.
Is a 2 or 3 sigma fluctuation worth a lot of press? Personally, I don't think so. But we don't know if it's a fluctuation yet, and no institution is going to pass on having made it clear, if this does turn out to be real, that they were involved.
All that being said: I would very much like these folks to continue to receive funding. They are professional and do excellent work, as demonstrated here.
Absolute and utter ridiculous nonsense. Can you not just admit when you're wrong?
It's perfectly ethical for them to give a talk at TeVPA about a paper they've published.
But at least 8 global, coordinated press releases? That's a choice, with consequences.
And one of those consequences is that they reveal themselves as chasing funding above all else. Scientific rigor goes out the window. 2.6 sigma results become amazing new discoveries.
It's not really their fault - it's systemic. But don't try to pretend that this is somehow the normal process of science being conducted with integrity.
> Absolute and utter ridiculous nonsense. Can you not just admit when you're wrong?
Wrong about what? If you think they should _not_ just report their findings, and instead try to change their analysis after already finding this event, then you're free to think that, and you're also free to say so. Personally, I don't think that that would be ethical.
> But at least 8 global, coordinated press releases? That's a choice, with consequences.
You seem to be asserting that there is something of nefarious happening. The collaboration does coordinate otherwise-unrelated releases by individual institutions. The alternative is that PR folks distributed across different institutions, few if any of whom have any training in physics or statistics, would make whatever claims they feel appropriate at whatever time they feel appropriate (relative to each other, and relative to publication of the actual paper). In what way is that preferable?
> 2.6 sigma results become amazing new discoveries.
They are not claiming a new discovery. They are claiming to have observed a single event, which is significant at the level of 2.6 sigma. A naive treatment produces a significance of more than 3 sigma, and the collaboration did what you might call "extra" work to be fair in their statistical analysis, which reduced the appropriate number to quote to be below 3 sigma. They state that clearly, and suggest interpreting the event at 2.6 sigma, the less-flashy option. To me, that shows integrity.