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  sotiris-k

  Oct. 14, 2006, 12:14 a.m.

  The baryon antibaryon equivalent to the lepton antilepton positronium where the bound state is between electron and positron . Nice enough to be studied crudely with elementary quantum mechanics but probably a tough exercise to calculate lifetime expectancy and correct binding energy using strong interactions as important contribution to the electromagnetic one. If the effective radius is close to a fermi the last ones are conceivably more important than electromagnetic ones that define almost all chemistry for the rest of elements and isotopes. Anyone up to doing the calculation for lifetime and radius? Lifetime quoted is close to an eternity in particle physics. To see how tough this system is to study try the positronium study in Quantum Electrodynamics by Greiner -Reinhardt. Then good luck adding hadrons to the mess already witnessed above!

  Impressive how wikipedia is already up to it with today's date!

  http://en.wikipedia.org/wiki/Protonium

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    geographer47

    Oct. 14, 2006, 2:49 p.m.

    It's another of the unexpected discoveries that make science so fascinating and it underscores Haldane's observation that not only is the universe stranger than we suppose, it's stranger than we can suppose.

    One of the reasons to build places like CERN is because we can't begin to guess what they might discover.
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  dr-don-from-denver

  Oct. 14, 2006, 10:05 a.m.

  I get it...You get TWO-TWO-TWO matter forms in one!! Just like Certs, only scientific!
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  Eduard

  Oct. 14, 2006, 1:19 p.m.

  Are you saying that the make-up of particle physics is the same substance only bound different sort of like clay that can be formed into various images but the same until we enter math. Time to para quote Einstein for he said math is the limit to the human thought and we may not resolve a problem with mans thinking. We need the quantum leap or use the theory that to advance is to take a step in either direction. As far as the calulation goes its simple if its real anti-matter. 0-0=-0
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  Sachmo499

  Oct. 14, 2006, 1:50 p.m.

  They are going to hurt themselves.
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  Virginia

  Oct. 14, 2006, 5:37 p.m.

  From the CERN site: "A visit to the Laboratory

  Discover the gigantic underground ATLAS experiment. Sunday 15 October. For reservations call 41 22 767 76 76. CANCELLED FOR TECHNICAL REASONS." What happened?

  The experiment cited in this article happened in 2002 at CERN. Why now is it coming to light?
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  Graham_Graham

  Oct. 14, 2006, 5:50 p.m.

  ' The experiment cited in this article happened in 2002 at CERN. Why now is it coming to light? '

  It wasn't expected, it only came to light after analysing it to such a point, I presume.

  How do you find something you're not looking for? Sometimes it's obvious, sometimes it's not..

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    Virginia

    Oct. 14, 2006, 6:05 p.m.

    Good guess. Mostly I think there are 'what if' scenarios and then search to find out from past experimental data if this is possible. Any others?
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  sotiris-k

  Oct. 14, 2006, 6:36 p.m.

  This experiment is indeed done in 2002. I guess they didnt study the results to publish or draw any conclusion from until lately . It does not represent a discovery that people didnt expect or learned something extremelly unexpected from . Think of it as a fun experiment. A physicists' lets have some fun study. A simple enough system to imagine and experimentally realize , to test your theory about strong interactions and QED but not in a way that you learn new physics from but rather from a point of view of an exercise. The idea you can have a bound state with a matter antimatter pair is very old probably as old as antimatter discovery in the 30s. There are books studying as exercise in QED the properties of positronium (electron positron pair). To do the hadron equivalent proton antiproton is the next step. Think of it as something that someone would eventually do for fun .
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  sotiris-k

  Oct. 14, 2006, 6:45 p.m.

  Now it may appear as pointless but try performing the calculations involved and see how its actually an interesting little experiment to figure out how well you can handle your knowledge in QED and QCD. Trust me its a very elaborate caclulation that has actually somethingt o do with real nature! People have played with such exotic atom like systems for a long time. For example one can create a different version of hydrogen atom using instead of electron its cousin muon an unstable lepton that deacys in 10^-5 sec. Insteaf of e you have a mu interacting with the nucleous (proton) . Muon has 205 times the mass of electron so the resulting atom is very different in energy levels, radius etc. Its much smaller in size. It is also shortlived since the muon eventually decays . However notice how it has been suggested that creating such an intermediate state like a muonic atom could catalyze nuclear fusion by bringing closer protons electromganetically shielded by the muon .
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  sotiris-k

  Oct. 14, 2006, 6:53 p.m.

  Indeed it has been shown that fusion is accelerated with muonic atoms involved. It requires lower temperatures. Unfortunately other properties of the resulting system including how many times a given muon can be used to catalyze reactions before it decays plus the fact that to create a muon requires energy restricts its applicability. But the game is not over regarding this idea as it may inspire something better in the future or it may be modified and performed in environments that enhance its advantages.

  The bound state mentioned in the article is very different but along the same line of exotic atom like bound states. It probably wont play a role in future matter antimatter propulsion but then again its study may motivate some other idea or enhance our calculation application of QCD. In science usually the utility of something that appears so removed from every day reality becomes obvious a lot later so you need to embrace every little thing even long before it appears useful.
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  lfergie812

  Oct. 14, 2006, 7:35 p.m.

  Gee. When I went to school, we were told that an atom was made up of three particles. Electron, proton, and neutron and all matter was made up of combination of these particles. What will the next fifty years bring?

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    sotiris-k

    Oct. 15, 2006, 1:22 a.m.

    Your school education is safe for 99.99999....999999% of things out there. Those other bound systems are exotic ,so unstable, not particularly useful yet in any applications .However that might change . They are simply trying to change one or more of those classic atom ingredients ie electrons to antiprotons,to observe the new bounded system that forms. It would be amazing to create a stable bound system that has exotic properties or catalyzes other phenomena . Nothing comes to mind yet but it might ;-)

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      geographer47

      Oct. 15, 2006, 9:40 a.m.

      As soon as I picked up on the concept of bound systems of unconventional particles, the possibility of stability crossed my mind. Does theory suggest what properties various pairings would have or does that have to be studied if and when it happens?

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        sotiris-k

        Oct. 16, 2006, 6:34 a.m.

        Current theory predicts well most of those exotic systems. Even if it doesnt do so perfectly (rarely) its mostly due to the very complicated nature of interactions taking place and the toughness to produce a clean easy calculation rather than the lack of visualization from the part of the theorist of the procedures taking place and the parameters that matter. Systems like muonic atoms or positronium have been studied extensively for the past 40 years and they are very much predicted in all their properties to excellent experimental accuracy years later. The real tough situation where things are not so clean is in very high energy collisions where very soon new physics will very likely be seen . There theory is still at work and possibly clueless at times. The kind of experiments that produce exotic bound systems are so very low energy ones that can be tackled easily from a conceptual point of view although at times the calculations may take pages to perform to required accuracy or several computer program lines of calculational codes (eg with Maple or Mathematica etc). Its really a thing of beauty to see how close theory can predict those systems well before observed . Some of the most confidence boosting instances in human history can be realized in modern theoretical particle physics.
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  ameliog

  Oct. 15, 2006, 12:39 a.m.

  Any guesses from the smart people yet as to an application for this? Energy, doomsday device, what? Help me Mr. Wizard!

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