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Matter-Antimatter Bias Seen In Fermilab Collisions
ubermiester writes "The New York Times is reporting that scientists at Fermilab have found evidence of a very small (about 1%) average difference between the amount of matter/antimatter produced in a series of particle collisions. Quoting: '[T]he team, known as the DZero collaboration, found that the fireballs produced pairs of ... muons ... slightly more often than they produced pairs of anti-muons. So the miniature universe inside the accelerator went from being neutral to being about 1 percent more matter than antimatter.' This finding invites theorists to explain why there is so much more matter than antimatter in the universe, when the Standard Model suggests that there should be equal amounts of each." Here is the paper as submitted to Physical Review (PDF). The DZero team is looking forward to getting detailed data from the LHC once it ramps up operationally.
For some experiments, 1% might be attributable to error. I've never done practical particle physics, though. Does this fall under experimental error, or is stuff like this usually re-creatable to seventeen decimal places?
I may not know much science, but I do know that margin of error is important.
So presumably 99% of the mass-energy in the universe is currently energy, much of which must be potential and kinetic energy. The momentum of the Big Bang, the energy we will get back in the eventual collapse, light elements which will eventually fuse, and heavy elements which will eventually undergo fission.
http://michaelsmith.id.au
It would be so funny to discover now that the laws of physics are uneven in space...
That the same experiment gets you different results depending on which sid of the Milky Way you are...
Or they could be uneven in time. Maybe every 54.12 years the relation between produced matter/antimatter switches from 1:1.01 to 1.01:1.
I'm probably misunderstanding something here, but it seems that they have discovered that when the big bang happened, then because of this property, a bit more matter was created than anti-matter out of wherever they came in the first place, the rest of it annihilated with each other and everything else is made up from the "extra bits". This seems fairly reasonable.
Now, it is also known that new matter-antimatter element pairs are being created and annihilated all the time everywhere, this is where Hawking radiation comes from.
Does this new discovery mean, that it would be possible, that instead of an antimatter-matter pair a matter-matter pair is created sometimes instead and therefore the amount of matter in the universe is increasing (even if by a tiny amount)? Or are the conditions needed for this to happen too extreme to ever take place outside of big bangs and accelerators? Although as I understand some cosmic rays have far greater energies than accelerators.
Real physicists - please help me make sense of it all!
I am SO cool I can keep meat fresh for a WEEK!!!!
The Tevatron is so thoroughly outclassed by the LHC that they have to take advantage of every opportunity to make a press release and show that they are still relevant. Once the LHC starts producing science data there will be impossible to justify funding for the Tevatron. The whole of Fermi Lab. (which uses about half the science money given by the D.O.E.) will be in danger of being closed, so they are fighting for survival. During the Bush administration they had to get private funding to avoid lay-offs. http://tierneylab.blogs.nytimes.com/2008/07/02/good-news-or-less-bad-news-for-american-science/
I know modern science is meant to be collaborative, but this paper has more than a page of authors! I note that they are listed alphabetically -- remind me to change my name to Aarons before taking up particle physics.
This is typical of "big science" that involves tons of people like experimental high energy versus "bench science" or "desk science" like everyone else.
The only possible interpretation of any research whatever in the 'social sciences' is: some do, some don't
That was a great explanation, many thanks! Only one part seemed a bit too sketchy:
Something doesn't make sense in that description though, regardless of the asymmetry. Matter and antimatter coalesced out of a higher energy state in the Big Bang, so why would they appear only to immediately annihilate themselves against each other into energy again? Except for the tiny asymmetry, the before-and-after states of this process are identical because of energy conservation, so unless some other property changed as well, in effect it didn't happen.
In practice it wouldn't be a process of appear+annihilate at all, but a gradual cooling down of the high energy state through spacetime expansion until only the 1 in 10^9 asymmetric part remains. The sudden appearance and annihilation as two separate steps is completely artificial, and I don't see why that part of the Big Bang is being described that way, even in a theoretical model.
The Tevatron has to be partially removed to allow the construction of Project X, which is an accelerator that complements the LHC but does not compete with it. Fermilab is in no danger of being closed due to obsolescence. Many of the people who work there are working on the LHC, and there are many other experiments located at Fermilab.
After congress canceled the Superconducting Super Collider, Europe focused on exploring the "Energy Frontier" and American scientists have focused on the "Intensity Frontier." There are also lots of collaboration and experiments that do not fit into either category. Of course, the rate at which the "Intensity Frontier" is explored does depend on the federal budget, but it will get done eventually.
Simon's Rock College
As someone that checked out of physics qight before the Modern Physics track (I'm an engineer, and not of the nuclear variety, I have no use for such tiny things), and someone that has read about this sort of thing (sub atomic particles and their many wonderful interactions and breakdowns) in other publications, I wonder if perhaps this particular pairing of particles may indeed have a true imbalance in matter-antimatter breakdowns, but may be balanced by another pairing that may have an antimatter bias, thus having a balance in a "bigger picture" so to speak? Since so much at this scale is a blurring of real particles/energy waves and mathematical constructs that exist to explain something observed experimentally through interactions with other particles or waves, I am not finding it convincing that conservatin of charge is really violated, or if perhaps some as yet unexplained particle/wave/energy phenomenon may be occuring in that ~1% of reactions that carries off the detectable balancing charge from the reaction.
The last time I looked at a list of the theoretical particles that make up the Proton, Neutron, and the Electron, and then the particles that make up those particles, it filled a page with their names and short explanations. We're at a scale where stuff has to be mathematically infered based on observations that are too small to be directly measured and have to be done indirectly through other measurements. And, we have no real idea if what we're measuring is the smallest possible entities/quanta of energies that make up these particles, or if there are still smaller bits of matter/energy that go into making up these items that we are looking at. It's like trying to examine one card near the base of a house of cards made up by arranging millions of decks of cards that's the size of the Taj Mahal. What about the fibers that make up that card? What about the particles that make up those fibers? Can those particles be further borken down? How would we know? We can't directly interact with the fibers, much less the particles that make up those fibers. It's amazing to me that we've come this far with our understanding of how these things work and are arranged. To use the above analogy, to look at that one card we're trying to find out about, we're having to take another deck of cards and throw it at the taj mahal sized house of cards at a non-trivial fraction of the speed ofl ight and hope that there is a possibility that we can see where that one card managed to hit another deck of cards arranged in another house about 5 miles away and we can accurately discribe how it hit it, what happened when it hit it, and what happened immediately after it hit it.
This is why I'm not a high-energy subatomic physicist, I can't get my mind around those concepts enough to make myself believe that we're seeing what we're seeing.
I have just three words on this:
"Alternating Neutral Currents".
(For those confused, Neutral Currents are interactions mediated by the Z boson. In the early 1970s, there was a race on to provide evidence for these, and there were press releases that had to be retracted because somebody jumped the gun and reported finding a Z before it was verified. This jokingly became called 'Alternating neutral currents', and several physicists had their credibility rather damaged in the process...)