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STAR Collaboration / RHIC / BNL
This image shows a three-dimensional rendering of the STAR time projection chamber surrounded by the time-of-flight barrel (the outermost cylinder). Particle tracks spray out from the collision, including a meter-long track from an antihelium-4 nucleus (highlighted in bold red).
The reports began circulating a few weeks ago, and today's publication in the journal Nature makes it official: Physicists have detected the heaviest bits of antimatter ever found on Earth. And that record is likely to stand for a long, long time.
Members of the STAR collaboration at the Relativistic Heavy Ion Collider, based at Brookhaven National Laboratory in New York, say they've seen the traces of 18 nuclei of antihelium-4 among about half a trillion particles produced by almost a billion gold-ion collisions at RHIC. These nuclei are like regular helium nuclei, except that instead of having two protons and two neutrons, they have two negatively charged antiprotons and two antineutrons.
The particles existed for only about 10 billionths of a second before they came in contact with ordinary matter particles and were annihilated, but that was long enough to register on STAR's detectors. Physicists can routinely produce antihydrogen nuclei (basically, antiprotons), and last year a research team reported the first detection of antihydrogen atoms (a positron going around an antiproton). Scientists have even detected antihelium-3 nuclei (two antiprotons and an antineutron). But until now, antihelium-4 has eluded them.
RHIC is best-known for smashing together gold ions so forcefully that particles like protons shatter into their constituent quarks and gluons, producing the kind of primordial soup that existed just an instant after the big bang. When that soup congeals, all sorts of combinations of quarks come together — and statistically, there's an ever-so-slight chance that the quarks will arrange themselves into two antiprotons paired with two antineutrons. The odds of that happening are so vanishingly small that RHIC's researchers had to sift through mountains of data to find the 18 events they were looking for.
The bad news is that the chances of finding anything even heavier are even more vanishingly small. So small, in fact, that physicists don't expect to detect them anytime in the foreseeable future, at RHIC or even at Europe's Large Hadron Collider.
The good news is that these 18 detections confirm the statistical model that theorists expected to see for the creation of antimatter in the lab. Searching for natural-born antimatter in outer space is one of the top jobs for the $2 billion Alpha Magnetic Spectrometer, which is due to be delivered to the International Space Station a week from now. The AMS should be able to detect antihelium nuclei and other subatomic oddities during its years-long run in orbit.
If the AMS comes up with different statistical balances of antimatter vs. matter, that would suggest that a cosmic source of antimatter somehow survived the big matter-vs.-antimatter blowup that scientists believe followed the big bang.
"The new measurement from the STAR experiment would provide the quantitative background rate for comparison," said Hank Crawford, a STAR collaborator from the University of California at Berkeley, said today in a news release. "An observation of antihelium-4 by the AMS experiment could indicate the existence of large quantities of antimatter somehow segregated from the matter in our universe."
Such findings could shed further light on one of the big mysteries about the universe's origins: How is it that matter won out over antimatter, resulting in the cosmos as we see it today? Is it possible that we merely live in a localized zone of the universe where matter dominates? Could there be huge reservoirs of antimatter, on the other side of a DMZ (dematterized zone)? During the next decade, the Alpha Magnetic Spectrometer just might help scientists put together more pieces of the matter-antimatter puzzle.
More about the antimatter mystery:
- Exotic antimatter particle exhibits new conduct
- Antimatter atoms caught at last
- Weird antimatter particles discovered
- Could X particle solve two puzzles?
Correction for 3:10 p.m. ET April 25: I initially had the constituents of the nucleus wrong in the second paragraph. It's two antiprotons and two antineutrons, not two antiprotons and two antiprotons. Sorry about that!
Hundreds of scientists in the STAR Collaboration equally share the credit for the research reported in the Nature paper, "Observation of the Antimatter Helium-4 Nucleus." A version of the paper was made publicly available on the arXiv.org website.
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Leave a Comment:
Into the breach my friends, and to boldly go where no one has gone before. (star trek theme) :)
But Cap'n, the dilithium crystal matter/anti-matter reaction canna hold Warp Factor 5 much longer!!
Allellulia Mother o God particle..thank you christ !
OK. uhhh so what good is all this? If it lasts only less than an instant and wont sweeten my coffee, why should I care? How is this going to help the world?
Dave, the more we know, the more we can utilize to our benefit. Ice cream was invented purely by accident, and we all love ice cream, now don't we?
Dave, I was thinking the same thing. Trillions to one chance? Ok, so man has discovered a heavier particle with anti-proton properties that could be converted to a fuel source. But billions of collisions to produce? I'll take one ounce of anti-helium and I expect it to be delivered by Christmas year 5001
Welllllll ... This is one of those cases where the ultimate payoff is hard to predict. But if you consider that antimatter is already being used for medical diagnoses (in PET scans, positron emission tomography), you might be willing to concede that having a better understanding of how antimatter works could lead to further benefits. Maybe this kind of research will eventually lead to a "Star Trekky" matter/antimatter drive. Maybe it'll be something else. But a fuller understanding of cosmic mechanics almost always eventually leads to new technologies.
http://www.msnbc.msn.com/id/23594045/ns/technology_and_science-space/
A research question... Does anti-helium (3 or 4) 'weigh' the same as helium (3 or4)? For that matter, do anti atoms or particle weigh the same as ordinary atoms and particles? Could any difference be detectable? If there are differences...
If I'm not mistaken "Yes" they do have the same mass (I believe you meant to ask about mass, not weight). They are supposed to be exactly the same particles but opposite properties. So, inasmuch as they are the same particle, they are the same mass. Just rather than a negatively charged "electron" there is a positively changed "positron" (as opposed to a "proton" which is a different type of particle).
So, a proton and a positron are both positively charged but they are not the same type of particle and don't have the same mass. An electron and a positron are the same type of particle and have the same mass but have opposite charges (and some other properties, like spin, tilt, ect.).
Yes, the measured mass would be the same. That's how they judged the detections. They saw the signature of a particle that was roughly four times the mass of a proton but with a double negative charge. That implied the existence of two antiprotons (1 negative charge each) and two antineutrons. Eventually, physicists would love to make further measurements, including spectral analysis, to see similarities and differences between matter and antimatter.
I was thinking about weight in the sense of anti-matter being influenced by gravity. Just an imagine; but suppose gravity was just a form of energy that was associated with anti matter. (not a property of space). If gravity could be created and transformed just as the various forms of what we call energy, then there might be residual gravity in space? The constant of gravity might change over time; but time related to anti mater prevalence - not time as such. If in the early universe anti matter created (or was created from) gravity, how might that effect what we see today?
Are the collision of two matter particles exactly the same as the collision of their two anti matter counter parts? Are there any studies of anti matter and anti matter particle collisions and how they compare to their matter cousins? Future studies of how anti matter is effected by gravity are fascinating - thus my question about 'weight'. What if gravity could be created or altered?
I find such thoughts fascinating and I have no emotional attachment to any of this being 'true'. In any case, if one can not imagine the impossible, you may not notice it should it appear.
Feel free to tell me how impossible any of this is.
If I remember correctly the theory that gravity is particulate is not new. It's embodied in the "graviton", but is as yet undiscovered.
en.wikipedia.org/wiki/Graviton
Thomas, it is so entirely possible to manipulate gravity in that it will allow a shfit in both weight and time as we have thus far perceived, giving us a new canvass to create entry into dimensions only hinted at by science fiction and religions.
"When that soup congeals, all sorts of combinations of quarks come together " ...it seems we're just duplicating the terrain for any infinite # of possible combinations which may or may not be discursive to the quantum we know. The indication is that the theory is being backed into. Keep those grants a-comin boys.
This sounds like interpretative mumbo-jumbo to me! If you have to sift through mountains of data to find what you expect should be happening and only for fractions of seconds in the fempto or pico, then it sounds like number manipulation and guesswork is in order! You are talking about particles that are beyond microscopic levels that cannot be seen or detected correctly. They are only guessed to occur due to statistics. Quarks, Gluons, cmon...Now you are talking millions of particles mixing together and you're looking for the one through compositional statistics? How would you measure such an experiement? Have we ever thought that some things are just not meant to be understood with the primitive equipment that we have? It's like smashing eggs with a sledgehammer and expecting to find the secret ingredient to life in the universe within the spilled contents. Wrong tools and wrong way to go about it! Maybe our maths are wrong too...Some things are not meant to be understood with conventional mathematics. These things extrapolate into quantum dimensions that we cannot see or detect conventionally. Like they said quantum packets they wink themselves into existence. Antimater, even though we know it exists but we don't know how to create it ourselves (smashing atoms is silly) since it theoretically can be done with manipulation of heavy isotopes not found on periodic table (missing from Mendelev table) I just think our formulas for creating it are primitive and wrong. Babysteps into the darkness. The stars have the answer...
Way to fit the least amount of ideas into the most amount of words, working_class. 0/10
I was a bit unclear about this in the 2nd paragraph:
So are there 4 antiprotons, two of which have negative charge and the other two ????
That's the problem when trying to explain this type of research to the masses... they only see the negatives and not the positives.
@ Fianchetto
It should read two antiprotons and two antineutrons. Alan made a boo-boo.
nuttin wrong with babysteps
most people craw before they run
Mark et al., you're absolutely right. I made a booboo. Thanks for calling it to my attention, and sorry about the screw-up. I've fixed the text.
Your gripe is the exact reason they are doing these experiments: to prove or disprove the math.
If you do the math for acceleration and find that at 3mins in you should have an instantaneous velocity of 30mph wouldn't you feel better if you went through the exercise and got a real-world reading of 30mph? Now you know your math is good, you can use that to base other math on.
This is how you build knowledge.
So, two negatively charged antiprotons would be just a proton right? Double negative rule applies here?
Theorietical physics seems like such complete and utter BS. Agree with working_class.
No, it doesn't work that way ... Two negatives don't make a positive in this case. These are antiprotons, and each of them carries a negative charge. That's what makes them anti.
What's up with the edit MSNBC? Tried to go back and correct my Theoretical misspell. Won't let me. Why do you persecute me such as this?
Sorry, Stonefeather, I think Newsvine allows a set amount of time for making fixes in comments, but then it's set in stone.
Also, if you were trying to simply delete certain letters (just the 'i' for example) you wouldn't be able to. The only way to do it is to type a letter and then delete what you want. I tend to think of this as "activating the text" again. It's very annoying, but if you are still within the time limits this is the way to make the edit about which you speak.
So, if you've spelled it "theorietical" and you want to delete the 'i' then you need to type any letter(s) and then go and delete the 'i'.
good...now we can turn the d a m n thing off and go home...
negative is positive and positive is negative...hover through the fog and filthy air....
*For clarity's sake, I am going to write as if I'm sure you have a basic understanding of WHAT ANTIMATTER IS. Of course, even though your comment makes me wonder, I doubt one would say such a thing if they didn't have confidence in their knowledge on the subject. Also, I use bold and italics for emphasis, so don't take it badly. I use gestures. A LOT!*
First, there is of course the quest for knowledge, simply for the sake of understanding who & when and where from, etc.. BUT, to get to what you're wondering about:
Secondly, & the most OBVIOUS motivation, is to learn to mass-manufacture antimatter in large and efficient quantities, in a safe & controlled way. As the article said(perhaps implied is more accurate, but whatever), ENORMOUS amounts of energy are released when matter comes into contact with antimatter! Cleanly. If we could find a way to take normal matter, convert it into antimatter, and then simply combine the 2.... We're talking about amounts of energy that could be moved in pick-up trucks powering entire countries for years!
Third, and even more incredible, would be to learn about whether there is new antimatter produced continually, or at least a huge deposit of it, somewhere out there. I mean, I'm no over the top environmentalist or global warming berserk, but if you can't see even the slightest of the possibilities that CLEAN, CHEAP, INEXHAUSTIBLE SUPPLIES OF ENERGY promises, then why read this article?
And finally, just as important, in a more abstract way, is that nearly EVERY TIME we learn something new, subsequent discoveries are made as well. Look how far we've come, and how many incredible things have come about since the start of the "industrial,technological/codified & peer reviewed science age!" How many of us know that cathode ray TVs are based on ABSTRACT, THEORETICAL PARTICLE PHYSICS, JUST LIKE THIS!? CELL PHONES?! Now think of all the subsequent inventions and ideas have come from just THOSE TWO!
See what I mean?
Based on the energy input and antimatter output results of this experiment the amount of energy you could ever get back would be a microscopic fraction of what it took to generate the anti-matter in the first place. Not very efficient. Kind of like using coal to generate electricity to then use to split water into hydrogen and oxygen so that you can then recombine them in a fuel cell and get "clean" energy back out. You never come close to breaking even.
Now then, antimatter deposits in deep space might be interesting, if they turn out to exist, though I doubt they will. Problem is, how would you "harvest" it and bring it back here to use productively?
Of course, upon reflection... if it can be harnessed for energy, it can be harnessed for weapons.
There may be some lines we're better off not crossing.
That's something like what Albert Einstein told FDR in his now famous letter:
http://www.dannen.com/ae-fdr.html
but the overall intent of Einstein's communication was, in the end, don't let "them" (in that case Nazi Germany), get this weapon before we do. We proceded to develop the bomb, and here we are today.
I keep trying to weigh my anithelium, but my scale keeps blowing up. What should I do?