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Fermilab Not Dead Yet, Discovers Rare Single Top Quark
Several sources are reporting that in spite of LHC hype, Fermilab's Tevatron has produced another feat for scientific discovery. Currently the world's most powerful operating particle accelerator, the Tevatron has allowed researchers to observe a rare single Top Quark. "Previously, top quarks had only been observed when produced by the strong nuclear force. That interaction leads to the production of pairs of top quarks. The production of single top quarks, which involves the weak nuclear force and is harder to identify experimentally, has now been observed, almost 14 years to the day of the top quark discovery in 1995."
This quark was not charmed by being photographed.
No existe.
You might find Tomasso's piece better - he works with the CDF group.
http://dorigo.wordpress.com/2009/03/05/who-discovered-single-top-production/
How about explaining why protons have a +1 charge and neutrons have no charge? I'd say that's pretty useful. Ditto with explaining the charge of the anti-nucleons.
Hmm. The use of quarks are like saying what is the use of an child.
Coincidentally in this case the answer is the same: Nothing.
Just to be clear, this isn't a single/bare quark w/o a partner is it? As I thought isolating quarks outside of a hadron (w/ 1 or 2 other quarks) was not possible due to the nature of the strong force. Is what they are really saying is that they got an event to force just one top quark to decay once released from a hadron rather than 2 or more at once?
Actually, they don't explain "why" they have +1 charge. Merely elaborate on the idea that they do so.
Note also that the reason that protons have +1 charge isn't especially useful, in and of itself. Interesting, perhaps, but not useful.
"I do not agree with what you say, but I will defend to the death your right to say it"
Fermilab seemed to be counted out, no longer useful, with the advent of the LHC? How many recent science ventures turned out to be more useful than originally thought, and initially thought less useful than a replacement?
Space station? Hubble telescope? Mars rovers? ... you get the point. Why would anyone count Fermilab out? I just find that odd. Sure, it doesn't have the professed capabilities of the LHC, but then neither does the LHC right now. I seem to remember something about not fixing it if it ain't broke being relatively true.
I expect more from Fermilab too.
This is so much like American Idol or something ... gah!
Support NYCountryLawyer RIAA vs People
Interesting, perhaps, but not useful.
All the more reason to teach it. We should be trying to get students interested in science.
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I think that what this actually demonstrates is that it isn't the size of the accelerator that matters -- it's how long you can keep it running before it explodes.
I thought unbound (single) quarks were didn't exist?
-Bucky
You aren't quite grasping what he means by one in four million. This wasn't a single event we are talking about here.
The way the statistics work is that you would have to run the entire Fermilab experiment four million times to get what they see from a fake signal. It's a cumulative probability over all the events ever recorded at Fermilab.
They didn't detect it directly. The key to 'detecting' the neutrino is to count up everything else in the remnants collision and notice that it recoils off of something that you didn't detect. It acts as though what you can see in your detector is violating the conservation of energy. But in reality there's an undetectable neutrino zipping through the detector. So you calculate how much energy and in which direction such a neutrino would travel in order to conserve energy, and that's where they get that little diagram.
One of the things single-top is sensitive to is the coupling strength of the top and bottom quarks via the weak force. The value of this coupling is tightly constrained if one assumes that there are only six quarks (ie. there are three generations of matter). The fact that they measured it and it's within the six quark ballpark means that it is very likely that there isn't another pair of quarks waiting to be discovered.
The basic idea is that if the top and bottom coupling strength is measured to be less than the value we expect for six quarks then that means that some of that coupling strength actually goes to a different, seventh or eighth, quark. But I'm grossly simplifying things here for the general slashdot crowd.
Fission doesn't have to be the wasteful, inefficient, and proliferation-prone mess that it is today. There are more efficient, less proliferation-prone ways to provide fission-based power than wasting 98%+ of the energy in the fuel rods and storing the 'waste' in the open.
Most estimates place the reserves of usable fuel for breeders at 600,000+ years at current consumption. That's not bad!
I agree that fusion may well be the best answer, but do we have the luxury of waiting for it to be ready for prime time? I think we should invest in breeder technology until we can get fusion up and running reliably.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
Rueters, Batavia IL: Citing a weak nuclear force and inability to provide satisfying quantum entanglement, a local Top Quark has cancelled his EHarmony.com account and given up on finding a paired partner. "I feel like I'm decaying into something strange. I'm down all the time. At the bottom of my barrel. It's sort of like I'm never quite sure of where I am, or where I'm going, or at least not both at the same time," said the disappointed fundamental particle of creation.
EHarmony.com representatives say they tried to talk the depressed 31x10^-33year-old, but were unable to convince him to keep his account active. "We don't offer refunds, but we did him an additional 6 femtoseconds to find that scintillating someone."
When interviewed, the parents of the particle, also expressed disappointment. "We were hoping he'd find a Jewish girl, get married, maybe give us a little boson someday. Where did I go wrong?" sobbed his mother. "He'll be fine, honey" said the quark's father, comforting his wife. "After all, we had to go through 20 billion collisions to find each other, didn't we?" The father, a well-respected lawyer and his wife, a homemaker, live in Hackensack but speak to their son regularly.
Looking at his latest matches, the Top Quark sighed. "Mom and Dad are so different. He's a proton, she's so totally anti-proton. I don't know. If they could find each other, why can't I find anybody?"
Are the top quarks rarer than the sub bottom quarks?
Yes, but they wear one of eight different colors of gluon in their left pants pocket so you can identify them easily.