"We started out looking for dark matter and we didn't find it," he said. "Instead, we found other things that have been challenging for theory to explain."
[...] In particular, the team confirmed that when an atom's core, or nucleus, is overstuffed with neutrons, it can still find a way to a more stable configuration by spitting out a proton instead.
[...] When people imagine a nucleus, many may think of a lumpy ball made up of protons and neutrons, Ayyad said. But nuclei can take on strange shapes, including what are known as halo nuclei.
Beryllium-11 is an example of a halo nuclei. It's a form, or isotope, of the element beryllium that has four protons and seven neutrons in its nucleus. It keeps 10 of those 11 nuclear particles in a tight central cluster. But one neutron floats far away from that core, loosely bound to the rest of the nucleus, kind of like the moon ringing around the Earth, Ayyad said.
[...] In 2019, the researchers launched an experiment at Canada's national particle accelerator facility, TRIUMF [...] It looked like the beryllium-11's loosely bound neutron was ejecting an electron like normal beta decay, yet the beryllium wasn't following the known decay path to boron.
The team hypothesized that the high probability of the decay could be explained if a state in boron-11 existed as a doorway to another decay, to beryllium-10 and a proton. For anyone keeping score, that meant the nucleus had once again become beryllium. Only now it had six neutrons instead of seven.
"This happens just because of the halo nucleus," Ayyad said. "It's a very exotic type of radioactivity. It was actually the first direct evidence of proton radioactivity from a neutron-rich nucleus."
[...] But science welcomes scrutiny and skepticism, and the team's 2019 report was met with a healthy dose of both. That "doorway" state in boron-11 did not seem compatible with most theoretical models. Without a solid theory that made sense of what the team saw, different experts interpreted the team's data differently and offered up other potential conclusions.
[...] "The work is getting a lot of attention. Wolfi will visit Spain in a few weeks to talk about this," Ayyad said.
Part of the excitement is because the team's work could provide a new case study for what are known as open quantum systems. It's an intimidating name, but the concept can be thought of like the old adage, "nothing exists in a vacuum."
[...] Open quantum systems are literally everywhere, but finding one that's tractable enough to learn something from is challenging, especially in matters of the nucleus. [...]
But this detective story is still in its early chapters. To complete the case, researchers still need more data, more evidence to make full sense of what they're seeing. That means Ayyad and Mittig are still doing what they do best and investigating.
(Score: 2) by Snotnose on Monday July 25 2022, @09:08PM (2 children)
A) How does this relate to the theorized Island of Stability?
B) Are you really claiming nuclei that don't match your model are evidence of dark matter? Cuz I call horse hockey on that.
Disclaimer: I'm a math major with exactly 1 semester of Physics and Chemistry. But I can bedazzle you with how much I've forgotten about diffy Q's.
I just passed a drug test. My dealer has some explaining to do.
(Score: 2, Interesting) by Anonymous Coward on Monday July 25 2022, @09:29PM
Apparently there is a particle model that suggested that a certain unique decay could occur involving the ejection of a dark particle from a nucleus, and that is what they set out to look for. However, they didn't see that kind of decay, but they saw a different kind (that has nothing to do with dark matter) that was an oddball: a proton getting kicked out of a neutron-rich nucleus, as opposed to a neutron turning into a proton and kicking out an electron. These kind of decays fit a halo model of a nucleus where you have a neutron loosely hanging on similar to a valence electron loosely hanging around, and is an example of an 'open quantum system,' which I couldn't tell you anything about.
(Score: 4, Insightful) by maxwell demon on Tuesday July 26 2022, @07:09AM
They didfind nuclei that don't match our model, and yet they say explicitly they did not find dark matter. I think that conclusively answers your question with “no”.
They had a very specific prediction of what they might see if dark matter existed. If they had found that, it would have been evidence for dark matter, because it was a prediction based on dark matter. They didn't, but they found something different. That different thing was not evidence of dark matter, and they never claimed it was.
I suggest you work on your reading comprehension.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by Rosco P. Coltrane on Tuesday July 26 2022, @12:40AM
sure sounds more attractive than Half-Life and dark matter.
(Score: 4, Interesting) by FatPhil on Tuesday July 26 2022, @04:03PM (1 child)
Googling lead me quickly to this: https://iopscience.iop.org/chapter/978-1-6817-4581-7/bk978-1-6817-4581-7ch1.pdf , which is specifically on the topic, and written by Jim Al-Khalili, whom I find a very approachable science communicator. (I'm currently enjoying a 3-part BBC documentary on the history of chemistry written and presented by him, for example. He might not express the 'feels' and sense of wonder that draws in the younger viewers, but he delivers the science more directly, and more clearly, so he totally shits on Cox. You can quote me on that.) I'm only a couple of pages in, and there have already been a couple of "oooh, that's interesting" moments.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 3, Informative) by hubie on Wednesday July 27 2022, @02:39AM
Thanks for that link. I really enjoyed reading that.
(Score: 2) by Gaaark on Thursday July 28 2022, @09:45PM
Hmmm... more looking for dark matter, more not finding.
Sounds familiar, but YEAH... keep on looking, baby. The ice cream is there..... yeah....
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---