Matter, Anti-Matter, and a New Subatomic Particle?
Posted by
ScuttleMonkey
on Saturday March 22, @01:41AM
from the those-quarky-particles dept.
from the those-quarky-particles dept.
sciencehabit writes "Physicists may have finally figured out why the universe contains more matter than antimatter. The key lies in a flaw in the relationship between the two and a potentially new subatomic particle. 'Other researchers, however, say the results, published today in Nature, should be interpreted cautiously. It could all be an effect produced by run-of-the-mill particles'."
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Origin of Antimatter Cloud Discovered 136 comments
Active Seti brings us news that astronomers have discovered the origin of an enormous antimatter cloud surrounding the galactic center. Data from the European Space Agency's "Integral" satellite indicated that the cloud's distribution is similar to that of a group of binary star systems containing black holes or neutron stars. From NASA's article:
"The cloud itself is roughly 10,000 light-years across, and generates the energy of about 10,000 Suns. The cloud shines brightly in gamma rays due to a reaction governed by Einstein's famous equation E=mc^2. Integral found that the cloud extends farther on the western side of the galactic center than it does on the eastern side. Integral found certain types of binary systems near the galactic center are also skewed to the west. Because the two "pictures" of antimatter and hard low-mass X-ray binaries line up strongly suggests the binaries are producing significant amounts of positrons."
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Run-of-the-mill particles? (Score:5, Funny)
Would that be, um, flour? The universe is held together by flour?
(Thought I should attempt to reflect the Luddite perspective. Everybody else commenting on this post is being far too intelligent and rational.)
Exceptionally Simply Theory of Everything (Score:4, Interesting)
Re:Exceptionally Simply Theory of Everything (Score:5, Informative)
Very good question...
I do work on theoretical particle physics at CERN, so I would be the kind of person to take Garrett's paper and make predictions for colliders/astrophysics from it. (and hence, find methods to prove/disprove it) I'm not currently working on his theory, nor do I know of anyone who is. I only looked carefully at his paper when I posted the above comment (though I knew about it). I previously understood that he claimed the Standard Model was contained inside E8. If that is true then there are essentially no new predictions, just an interesting coincidence. However I see now that his theory is not the Standard Model, but a SU(2)xSU(2)xSU(4) Pati-Salam model. This implies several new particles that could be seen at the LHC. Garrett claims several things which are not totally justified and require some more calculations to find out (for instance...that the gauge groups unify).
The Pati-Salem model is well-studied (though not currently -- it was popular in the 80's). It is often known as a "leptoquark" theory. However I do not see in Garrett's paper the particle content necessary to make leptoquarks, nor the particles (higgses) to break the SU(2)xSU(2)xSU(4) to the Standard Model's U(1)xSU(2)xSU(3).
I think the problem is sociological. Garrett made a big splash in the gravity community, but I haven't heard a peep from any of my colleagues in particle physics. I will ask around at CERN next week. I know of no good reason why people are not studying it more carefully and making predictions (though, I'm sure Garrett is, but his background is gravity, not colliders).
Flash in the pan? Lots of stuff in the popular press is. For instance TFA is probably an effect of non-gaussian errors, but by making a splashy title they've gotten themselves a Science magazine article. Garrett got his flash partly because of his non-traditional lifestyle. Moral of the story is that the things that appear in the popular press are usually "hero" or "eureka!" stories. But science is full of neither heroes nor daily eureka's. I could complain further about the state of science reporting...
Keep in mind that there are literally hundreds of theories capable of explaining TFA (assuming it's not a statistical fluctuation), and you won't hear about them in the popular press because they're not sexy and hard to explain. For instance, a 4th generation of quarks or a complex higgs sector. Garrett's theory might be one of them, we don't know yet. We don't usually explain these theories to the public because explaining 100 different complicated theories, 99 of which must be wrong...is probably a waste of the public's time. Instead, we'll turn on the LHC this year, which will undoubtedly generate tons of popular articles, and hopefully at least one mostly-correct theory. ;)
-- Bob
Re:Exceptionally Simply Theory of Everything (Score:4, Informative)
Glad I could be of service. BTW I think your "periodic table" comment is an apt description of the situation. I think what's missing is dynamics.
Rather than google, if you want to keep up with Lisi (or anyone else's) papers, I suggest the SLAC Spires database. For instance, this is Lisi's "exceptionally simple" paper [stanford.edu]. Click on the "Cited..." to get a list of citations. This is updated daily from journal sources, and more importantly arxiv.org. This database generally has topics of relevance to high-energy physics, astrophysics, and gravity. Another good database is the NASA Astrophysical Data Service [harvard.edu], here's Lisi's "exceptionally simple" paper [harvard.edu] on ADS. I warn you however, everything retrieved this way will be technical in nature.
This is what the web was invented for, by the physics community at CERN no less, and now days all our papers are freely available before they are sent to journals, and the public is welcome to read them. Indeed, I despise the "ivory tower" perception and think we are much better off by having outsiders look at what we're doing. I just with the popular press would wrap their heads around the idea of citing primary sources with a hyperlink....but I digress.
-- Bob
A Non-Surprise (Score:5, Insightful)
Astronomers noticed an anomaly. They dreamed up dark matter to explain it. Actually, they dredged it up -- the concept had been applied to other phenomena and always found not to be involved if it even existed. Then they set about looking for other signs that matched the theory, and in a fit of circular reasoning claimed it supported the hypothesized existence of the dream-stuff. Now that they're getting away with it so well that The Teaching Company even has a 12 hour lecture series on it for sale, it's encouraging others to invent all manner of invisible widgetons to blame it on, because hey, anyone can do science, but how many people get to dream up something imaginary and get taken seriously? Dream-stuff is sexy even if it doesn't exist. It gets you noticed. It gets you published, and if the publication is more a question than an answer, well, it's invisible or massless or some other quality which makes it unseen by everyone except you and your imagination.
I'm not buying until I see how they dismiss the previous workable theory based on entirely known quanta that predates this supposed discovery by 10 years.
...more like a non-result (Score:4, Interesting)
The problem the strong force is that it is so strong at low energy that our normal technique to calculate what is going on (called perturbation theory) does not work because, rather than small perturbations, the strong interaction causes huge changes. This means that theorists have to make approximations in order to calculate anything and so their results may well just show a flaw in their assumptions rather than a flaw in our understanding of physics.
An excellent example of this was with my grad student experiment which was also measuring CP violation but with kaons. Before our measurement the theorists were saying that there was absolutely no way at all they could have a certain parameter (epsilon'/epsilon) to have a value greater than 1e-3 and it would likely be a lot lower. So, we measured it at around 1.7e-3 and, lo and behold, the theorists adjusted their models and suddenly it was in agreement with theory.
So while this might be an indication of something new I am not yet convinces that it is anything more than an incorrect assumption in a QCD calculation somewhere. Such calculations are fantastically difficult and while in this case there are things that will make it easier, it is not yet convincing evidence.
Re:A Non-Surprise (Score:4, Insightful)
Ok I'll one-up you: I attended a lecture this week, on this particular paper, at CERN.
Because in addition to the expected effects, TFA claims NEW effects not explainable by the standard theory. So, we need a new rabbit. The original theory is NOT sufficient if their claims are not due to statistical fluctuations.
That's a pretty darn good description of the scientific method, minus your disparaging adjectives.
Yes anyone can do science. That's the point. Observe, Hypothesize, test. Proving/disproving your dreamed up theory is hard work, and that's what we do. If their observations were explainable by the current theory, they would have been shot down in 5 seconds by their colleagues, in a seminar, or in the journals, and you wouldn't be reading about it in Science magazine. Science is incredibly adversarial. We're all trying to kill each other's theories.
FYI, it's generally a bad assumption that some piece of science you read about in the press has a simple explanation, and the scientists are idiots.
-- Bob
Same old science... (Score:4, Funny)
then create.newParticle();
Else
publish.newTheory();
Re: (Score:3, Insightful)
Doctors once thought that wellness and illness wit
Re:Dark Matter? (Score:5, Interesting)
Re:Dark Matter? (Score:4, Insightful)
Re:Dark Matter? (Score:5, Funny)
Re:Dark Matter? (Score:4, Insightful)
Re:Dark Matter? (Score:4, Insightful)
Re:Dark Matter? (Score:5, Informative)
Re:Dark Matter? (Score:4, Informative)
Re:Dark Matter? (Score:4, Interesting)
Since we can't currently *see it* I'll also agree that because it is currently not directly observable it is therefore "Dark" and made of "Matter".
My point is; that it to call it "Dark Matter" and to be done with it leaves things rather vague. Science rarely is so succinct and simple.
Black Hole material is also "Dark Matter" as it too cannot be directly observed.
Enough effects and gravity of the Black Holes' "Dark Matter" exists on the non-dark observable matter nearby to their hypothesized locations to convince scientists that Black Holes do exist (in addition to the math working out decently).
Stephen Hawking is THE MAN.
For all we know, the mysterious "Dark Matter" could really be just a very dense repository of all of the discarded fruitcakes from around the universe. We don't know.
Scientists have an idea about what "Dark Matter" might be, and likely SOME of that will be correct, but chances are that a majority of it will be wrong. It will actually turn out to be something more complicated than 'matter we just can't observe' so it is now therefore decreed to be henceforth called "Dark Matter".
I believe that atoms once were the smallest particles known, that changed. So will this. It may turn out to just be star ash, but Maybe not.
It could be thousands of things or types of matter, likely even stuff that is NOT dark.
If we can make a B2 bomber into "Dark Matter" from the POV of a man by using it's stealth features and electromagnetic radiation adsorbing coverings, maybe there's just plain ordinary matter out there that is rather cold and covered with some cosmic stealth paint.
The math says it exists and there is enough circumstantial evidence that "something" is there. I doubt it has some mystical properties that make it invisible. There are other dimensions in the universe that mathematics has proven exist, maybe being close or intersecting in some way with matter in those other dimensions is actually causing the "Dark Matter" effect.
I hope to live long enough to see "Dark Matter" become as archaic a term as the body's 4 humors are now from my original analogy.
Re:Dark Matter? (Score:5, Informative)
No, it couldn't. One thing that is definitely known is that the dark matter is not made of regular atoms (baryonic matter). Baryonic matter is known to comprise no more than about four percent of the total density of stuff in the universe, versus about 25 percent for dark matter. If the universe were 25 percent baryonic, all sorts of measurements would come out differently than they do:
(1) The primordial abundance of elements, which is observed to be about 76 percent hydrogen and 24 percent helium and a trace of lithium, would be very different. See here [wikipedia.org]
(2) The signatures of acoustic oscillations in the Cosmic Micrwave Background would be much larger than they are observed to be. See here [wikipedia.org]
(3) Any extra baryons would show up in the hot gas between galaxies in large clusters, which is very accurately measured by X-ray satellites. See here [nasa.gov].
(4) Dark matter consisting of small condensed objects like Jupiter-sized planets would show up in gravitational microlensing [wikipedia.org] surveys. They don't.
We don't know what dark matter is, but we sure as hell know what it's not, and it is not ordinary matter that just happens to be dark. There are multiple, independent lines of evidence which support this conclusion.
Re:Star Trekkin' Across the Universe (Score:5, Funny)
Re:Star Trekkin' Across the Universe (Score:5, Insightful)
For example? Can you list some of these please?
Re:Star Trekkin' Across the Universe (Score:4, Informative)
Wikipedia has a concise and complete list of hypothetical and theoretical particles:
Hypothetical particles [wikipedia.org]
Photino - superpartner ofthe photon [wikipedia.org]
Gluino - superpartner ofthe gluon [wikipedia.org]
Gravitino - superpartner of the graviton [wikipedia.org]
Neutralino - superpartner of other neutral particles [wikipedia.org]
Charginos - partners of charged bosons [wikipedia.org]
Sterile Neutrinos - needed to explain LSND results [wikipedia.org]
Sleptons [wikipedia.org] and Squarks - supersymmetric partners of fermions [wikipedia.org]
Tachyons - particles which travel faster than light [wikipedia.org]
Higgs Boson - the origin of mass [wikipedia.org]
Graviton - mediates gravity [wikipedia.org]
Preons - substructure for quarks and leptons [wikipedia.org]
Graviscalar [wikipedia.org] and Graviphoton [wikipedia.org]
Axion - Peccei-Quinn theory to solve the strong CP problem [wikipedia.org]
Axino and Saxion - form together with the axion a supermultiplet [wikipedia.org]
Supermultiplet - supersymmetric extensions of Peccei-Quinn theory [wikipedia.org]
Branon [wikipedia.org]
X and Y bosons - predicted by GUT theory [wikipedia.org]
Magnetic photon [wikipedia.org]
Majoron - predicted to understand neutrino masses [wikipedia.org]
These are all theories. Maybe there should be an X-prize for someone who can come up with a desktop experiment that can prove or disprove one or more of these theories.
Re:Star Trekkin' Across the Universe (Score:5, Insightful)
In particle physics right now, the problem is that we have a model, the Standard Model, which we know is incomplete (doesnt include gravity for a start) but it more or less explains every experimental result we've every produced (neutrino masses are argueably accommodated with some small extension). We lack experimental data to even give us a hint what might be beyond it and this has been the case for a long time. So theory has had nothing to do but invent crazy models and wait for the experimentalists to catch up (which we hope to do this year, it'll be exciting). Hence why you see a lot of crazy models around with zero experimental evidence supporting them.
The other problem is that we are all tired and sick of the Standard Model, we want to know whats beyond it so people really really want to find evidence of new physics beyond it. This means that people are quick to jump on small effects and claim its new physics which is probably where you are coming from. Usually they get shouted down by the rest of the quickly community but it does happen with alarming regularity (see pentaquarks, 160 GeV Higgs last year as two recent examples). Whats worse is that for something like the result in the article, its an indirect evidence in a QCD environment which basically means there are so many effects going on, this could easily be explained by the Standard Model. So basically nobody believes it for now. QCD is what binds mesons (such as the B+,B0) and baryons (such as the proton and neutron) together. Unfortunately, we cant solve it right now, except for high energies so often there are many effects which later turn out just because we make a mistake in our approximations in order to get a solution. Compare with the CDF Run I jet excess which later just turned out because QCD effects werent being taken into account. This is the reason that physicists wont believe anything which says new physics right now unless theres a clear unambiguous peak in a mass spectrum, ie make and detect a new particle in your detector. Now this could be genuine evidence but we've all been here before so I think the community takes the feeling that we'll wait for more supporting evidence and for people to offer up alternative explanations before we say its new physics.
Re:A flaw? A FLAW? (Score:5, Funny)
Not a flaw...a design feature (Score:4, Interesting)
Re:Matter vs. Anti-matter (Score:5, Informative)