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New Particle Found, the Bottom-Most Bottomonium

Posted by kdawson on from the how-low-can-you-go dept.

PhysicsDavid writes "Collaborators on the BaBar experiment at the Stanford Linear Accelerator Center have detected and measured, for the first time after a 30-year search, the lowest energy particle of the 'bottomonium' family, called the eta-sub-b. Bottomonium consists of a bottom quark and an anti-bottom quark bound together by the strong force. The discovery fills in a missing piece of quark physics that will help reveal the nature and behavior of the quarks and the strong force."

12 of 119 comments (clear)

  1. Huh? by Millennium · · Score: 5, Interesting

    Shouldn't a bottom quark and an anti-bottom quark annihilate one another? How do they manage to avoid doing so in this 'bottomonium' state?

    1. Re:Huh? by Remus+Shepherd · · Score: 5, Informative

      The same way protons and electrons avoid crashing into each other. The energy states are discontinuous and do not include zero. Once the bottomonium meson reaches its lowest state, it can't lose any more energy, so it can't get close enough to annihilate.

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    2. Re:Huh? by Steve+Max · · Score: 5, Informative

      They will annihilate after some time (the particle's lifetime), but they can be bound together for some time before that happens. Another good example is the \pi^0 (neutral pion), which is made of up and anti-up (or down and anti-down) quarks. It decays after some time to two photons.

      I don't know what is the lifetime of this \eta_b particle or its main decay branch (I haven't RTF BaBar's A and I'm not a QCD specialist), but it should be very short, and the main decay channel should be hadronic (ie, particle jets).

  2. Lowest energy particle found in California! by BadAnalogyGuy · · Score: 5, Funny

    Is it any surprise that the most laid back particle evar was discovered in California?

  3. bottom and anti-bottom? by spooje · · Score: 5, Funny

    The bottom and anti-bottom held together by the strong force?

    Sounds cheeky to me

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  4. Re:I am looking for a physicist here... by Anonymous Coward · · Score: 5, Informative

    They exist in groups of two or three that create a neutral color charge. For example, a particle can consist of red, green, and blue or of blue and anti-blue.

  5. Re:I am looking for a physicist here... by Jamu · · Score: 5, Informative

    They just have to be "color"-neutral so (red, green, blue) and (red, anti-red) are both allowed.

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  6. Re:Oh jeez, here come the bad jokes by TornCityVenz · · Score: 5, Funny

    Well this should certainly make Sir Mixalot very happy..... wait...nevermind.

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  7. That's pure, weapons grade ... by 0racle · · Score: 5, Funny

    bullonium.

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  8. Re:Oh jeez, here come the bad jokes by Anonymous Coward · · Score: 5, Funny

    Scientific Symbol: ASS.

  9. Re:Alternative Theory Tie in? by krlynch · · Score: 5, Informative

    The interesting question, IMHO, is: Was this particle predicted by anybody else's research?

    Yes. It's called the standard model. It's not surprising that it was found ... it would have been more surprising if it hadn't been found eventually.

  10. Re:I am looking for a physicist here... by krlynch · · Score: 5, Insightful

    I'm not surprised that I can't tell the difference between a proper description of quantum mechanics and the ramblings of a drunken madman on the street.

    I don't mean to sound like I'm ripping on you, but QM isn't really that fundamentally "weird" or difficult to understand, or "odd" at this point in history; it's not any more complicated to wrap your brain around than classical mechanics, or E&M, or automobile maintenance. The "romance" that QM (like Relativity) is "hard" is, I think, a remnant of early popularizations of cutting edge research in the 1920s and 1930s, when a coherent theoretical framework was under construction for the first time, and physicists didn't really know how far down the rabbit hole went. Popularizers were desperately flailing around, looking for analogies that a much more rural and less technically sophisticated public could understand, and to whom they had trouble relating (the "they're all bumpkins" fallacy). We physicists were pretty inept at doing so then, and have been particularly inept at eradicating those early and incorrectly popularized notions from our public interactions to this day.

    Today, we should know better ... most of QM is robust and mature enough that it's an engineering discipline, for cripes sake. Hopefully, the popularizations will catch up with the reality at some point, and we won't keep subjecting generations to the "QM is so weird you can't possibly understand it unless you're a genius" meme.