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Physicists Discover "Doubly Strange" Particle

Posted by CmdrTaco on Thu Sep 04, 2008 08:28 AM
from the and-it-fits-in-the-palm-of-your-hand dept.
Tsalg writes "Physicists have discovered a new particle made of three quarks, the Omega-sub-b. The particle contains two strange quarks and a bottom quark (s-s-b). It is an exotic relative of the much more common proton and weighs about six times the proton mass. This is probably one of the last noticeable sub-atomic discoveries made somewhere else than at CERN since LHC is about to start the hunt for the Higgs particle that remains elusive even for the experiment that just discovered the Omega-sub-b."
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  • by Pat Attack (1353585) on Thursday September 04 2008, @08:32AM (#24872641)
    Sometimes I think physicists are just making things up. This is one of those times.
  • by Instine (963303) on Thursday September 04 2008, @08:33AM (#24872649) Homepage
    Can someone translate that last sentence for me?
    • Sure. Quarks are one of the two basic building blocks of matter, the other being the lepton. This particular particle -- a baryon, since it is comprised of three quarks -- consists of two strange quarks and one bottom quark. Strange quarks and bottom quarks are both very unstable. Another example of a baryon is the proton, which contains two up quarks and and a down quark. Up and down quarks are generally, by comparison, very stable. The instability of the quarks make this particular baryon difficult to detect.

      • by Anonymous Coward on Thursday September 04 2008, @11:42AM (#24875607)

        Call me when they put together the particle consisting of 2 up quarks, 2 down quarks, a left quark, a right quark, a left quark, a right quark, a 'b' quark, an 'a' quark, a 'select' quark, and a 'start' quark. ;)

    • by eln (21727) on Thursday September 04 2008, @09:00AM (#24872969) Homepage

      For reference, the last sentence is:

      This is probably one of the last noticeable sub-atomic discoveries made somewhere else than at CERN since LHC is about to start the hunt for the Higgs particle that remains elusive even for the experiment that just discovered the Omega-sub-b.."

      It's really quite simple to translate. It means that this will be the last noticeable sub-atomic discovery made anywhere other than CERN, because other sub-atomic discoveries are going to be way, way too small to be noticeable. However, CERN is in Switzerland, where people are used to working with very, very tiny things like watch mechanisms, and so are more likely to notice these very tiny particles.

      The Higgs particle is simply another name for the "Higgs boson", which is a mythical creature said to roam the forests around CERN, although it may have just been a side effect of the earlier LSD experiments at that location. The Higgs boson is said to be 7 feet tall with bright red hair, red nose, and giant shoes (hence the name "boson", after Bozo the Clown).

      The Omega-sub-b, of course, is supposed to mean the "Omega-sub-basement", which is a room deep under the FBI building where J. Edgar Hoover used to keep his "alternative" wardrobe, but the submitter appears to have died while in the middle of composing the sentence.

      I hope this clears things up for you.

    • by florescent_beige (608235) on Thursday September 04 2008, @09:01AM (#24872993) Journal

      Can someone translate that last sentence for me?

      Done:

      Dit staat waarschijnlijk een op het punt van de laatste merkbare sub-atomic ontdekkingen ergens gemaakt dan bij CERN anders aangezien LHC is de jacht voor het deeltje te beginnen Higgs dat zelfs voor het experiment ontwijkend blijft dat enkel omega-sub-B. ontdekte.

    • by perspectival (906492) <zabinac AT nc DOT rr DOT com> on Thursday September 04 2008, @09:56AM (#24873823)

      This is probably one of the last noticeable sub-atomic discoveries made somewhere else than at CERN since LHC is about to start the hunt for the Higgs particle that remains elusive even for the experiment that just discovered the Omega-sub-b.."

      In actual English--with tenses--as it used to be used (which is now, as is evident, archaic):

      "This recent discovery [of the Omega-sub-b particle] will probably be the last *notable* subatomic discovery made before the Large Hadron Collider at CERN begins to operate, which is scheduled to happen in October of this year. The LHC will be used to hunt for the Higgs Boson, which has thus far remained undetectable, even by experiments such as this one, which managed to find the Omega-sub-b particle."

      * The author's clever-at-first-glance use of the adjective "noticeable" fails because it applies to "discoveries," and discoveries rarely go unnoticed, unlike grammar.

  • Hmm, ... (Score:5, Funny)

    by Loibisch (964797) on Thursday September 04 2008, @08:34AM (#24872671)

    ...that's strange.

  • by LotsOfPhil (982823) on Thursday September 04 2008, @08:41AM (#24872751)
    Hmm, I think that this is only a relative of the proton in that it too is a baryon (3 quarks). A proton is up-up-down, and this is strange-strange-bottom.
    The charge on the new one is -1, the charge on a proton is +1.
  • Strange + Bottom ? (Score:5, Interesting)

    by florescent_beige (608235) on Thursday September 04 2008, @08:43AM (#24872773) Journal

    Ok I thought quarks, leptons, and neutrinos were grouped like this:

    Group 1: quarks; Up & Down, lepton; electron, neutrino; neutrino

    Group 2: quarks; Charm & Strange, lepton; muon; neutrino; muon neutrino

    Group 3: quarks; Top & Bottom, lepton; tau, neutrino; tau neutrino

    So this newly discovered particle is made of quarks from two groups, the strange quark from group 2 and the bottom quark from group 3. Has that been seen before? I never knew it happened.

    • by Anonymous Coward on Thursday September 04 2008, @08:56AM (#24872935)

      Yes, it's been seen before. There's an ungodly amount of particles (even if you restrict yourself to baryons), in fact, including many weird ones - see http://en.wikipedia.org/wiki/List_of_baryons for instance, or locate a copy of the Physics Letters B/Review of Particle Physics, which dedicates ~150 pages to listing baryons (in my 2004 copy, that is; chances are it's even more today).

    • by n1ckml007 (683046) on Thursday September 04 2008, @09:28AM (#24873311)
      Ok so what about: up up down down left right left right b a start ?
  • Lamen (Score:4, Interesting)

    by tom17 (659054) on Thursday September 04 2008, @08:50AM (#24872861) Homepage

    OK, so I have been reading a lot about particle physics lately and find the whole subject fascinating, but there is one thing (amongst many things) that I am not quite understanding. I have looked it up and my understanding of particle physics is not "there" yet, or at least not enough to grasp this particular concept. Maybe I have just not read the right explanation.

    Can someone in here put it in a simple lamen explanation?

    The question is this:

    This Omega-sub-b particle contains two strange quarks and a bottom quark and weighs about six times the mass of a proton.
    A proton contains 2 up quarks and one down quark.

    Strange quarks have a mass of 95MeV, bottom has 4.2GeV so the total mass of the Omega-sub-b would be 4.39GeV
    Up quarks have a mass of 3MeV, down has 6MeV so the total mass of a Proton would be 0.012GeV

    This would put the Omega-sub-b at 365.8 times the mass of a Proton.

    So I am obviously not understanding how the masses of the quarks correlate to the masses of the fermions. What am I missing here?

    Thanks,

    Tom...

    • Re:Lamen (Score:5, Informative)

      by Ihlosi (895663) on Thursday September 04 2008, @09:02AM (#24872997)

      So I am obviously not understanding how the masses of the quarks correlate to the masses of the fermions. What am I missing here?

      IANAPP (particle physicist), but I guess you're missing the equivalent to the "binding energy". Just like the mass of an atomic nucleus isn't equal to the sum of the masses of the protons and neutrons in it.

    • Re: (Score:3, Informative)

      I'm guessing: E=mc^2.
      See for instance here [gsu.edu]
    • Re: (Score:3, Insightful)

      Read this: http://en.wikipedia.org/wiki/Hadrons [wikipedia.org]

      Note that the mass of a hadron has very little to do with the mass of its valence quarks; rather, due to mass-energy equivalence, most of the mass comes from the large amount of energy associated with the strong nuclear force.

      To me, this seems to mean that you do not simply sum the masses of the quarks that make up the hadron (a baryon being a kind of hadron).

      The image of a proton given in Wikipedia (http://en.wikipedia.org/wiki/Image:Quark_structure_proton.svg) represents the three quarks in a triangle. OK, so this is simply a convenient representation, but it may help to think of the masses of the quarks as being vector forces. E.g., 10GeV in one direction + 5GeV in the opposit

    • Brief explanation (Score:5, Informative)

      by Anonymous Coward on Thursday September 04 2008, @10:01AM (#24873943)

      The proton weighs a little under a GeV, most of which is binding energy. Since the u and d quarks have so little mass, you can effectively ignore it and look at the dynamical relationship of 3 bound quarks. This is why early models which treated protons and neutrons as different states of the same particle (called isospin symmetry) worked so well. The equation's not all that simple, since binding energy is itself a function of the masses of the quarks involved. The only real theoretical calculations are heavily computational lattice QCD simulations, and experiments like this are a good test of those calculations.

      As a sidenote, the headline makes very little sense. We observed a "triply-strange" particle, the original Omega, ages ago. What makes this special aren't the two s quarks per se, but their appearance alongside a bottom quark.

      IAAPP

  • by Anne_Nonymous (313852) on Thursday September 04 2008, @08:51AM (#24872869) Homepage Journal

    ...doubly strange, some quirks, and six times overweight.

    Ed, you're famous!

  • by RTHilton (1343643) on Thursday September 04 2008, @09:00AM (#24872973)
    Must be an American particle.
  • static? noise? (Score:3, Interesting)

    by acvh (120205) <geek@@@mscigars...com> on Thursday September 04 2008, @09:04AM (#24873015) Homepage

    They looked at 100 trillion pieces of data, and found 18 that they could call Omega-sub-b. Wouldn't this fall into the realm of randomness?

  • by Taibhsear (1286214) on Thursday September 04 2008, @09:55AM (#24873807)

    I was always fascinated by particle physics but it's been a while since I studied it. Can someone explain how a proton-antiproton collision (u,u,d quarks and anti-u,anti-u,anti-d quarks) could produce strange quarks? I thought all that was left after a matter-antimatter collision was x-rays and gamma-rays.

    • by jstott (212041) on Thursday September 04 2008, @12:01PM (#24875937)

      I was always fascinated by particle physics but it's been a while since I studied it. Can someone explain how a proton-antiproton collision (u,u,d quarks and anti-u,anti-u,anti-d quarks) could produce strange quarks?

      There are three fundamental forces that matter in a particle collider: the strong force, the weak force, and the electro-magnetic force. When the interactions are through the strong force (which is described by the theory of quantum chromodynamics [QCD]), the result is either things start to stick together or you create a pairs of quarks (a quark and its anti-quark, to conserve charge). These quark pairs can, in turn, either produce new pairs of quarks or they can stick and produce new particles. So, strong interactions can produce strange quarks out of nothing if you supply enough energy, but they'll always come in a strange/anti-strange pair. Given that the \omega_b has both a strange and an anti-strange quark in it, I'm guessing that it probably is coming out of a series of strong nuclear interactions.

      At low energies, electro-magnetic forces deal with the interactions of particles and photons, which is important but kinda boring (at high enough energies life is more complicated and EM forces become a kind of weak force, but that's getting off track).

      The final force, the weak force doesn't interact very strongly with particles (hence its name), so weak events are much less common than strong events. On the other hand, because they obey different symmetries, weak events can do some things that strong events can't do. In particular, weak events can change the flavor of quarks, for example, from a down quark to a strange quark. So, the second way you can get a strange quark from a bunch of up and down quarks is through a weak interaction that changes the flavor of one or more quarks.

      -JS

    • by jeremyp (130771) on Thursday September 04 2008, @08:46AM (#24872805) Homepage Journal

      That was my immediate thought too. Perhaps LHC emits some sort field that causes all other particle accelerators to mysteriously stop working. Yes, that must be it. European particle physics experiments are heavily influenced by fundamental particles called eurons and LHC has been sucking them up at a vast rate to the detriment of other experiments.

      • Re:Excuse Me? (Score:5, Interesting)

        by oldspewey (1303305) on Thursday September 04 2008, @08:54AM (#24872895)

        Perhaps LHC emits some sort field

        In Richard Florida's book Who's your city? he actually gets into various theories about how centers of excellence (whether fashion, IT, finance, science, etc.) tend to create a self-reinforcing "buzz" that draws in more and more talented people, and the intellectual atmosphere and other elements of creative infrastructure then allow those people to achieve at a higher level than they otherwise could.

        So according to that theory, yes, the LHC does emit some sort of field ...

    • Re: (Score:3, Informative)

      He's talking about the energy levels produced at CERN. While scientists anywhere will be making discoveries, it will likely be with data produced from experiments at CERN.
      • Re:Excuse Me? (Score:5, Informative)

        by The_Wilschon (782534) on Thursday September 04 2008, @09:36AM (#24873439) Homepage
        Won't happen. We're hard at work on it right now (except when we're reading slashdot...), and we're making some amazing leaps forward in analysis techniques, but we simply won't have enough data to be sufficiently sensitive to the Higgs by the time the accelerator shuts down. We might find evidence or even strong evidence, but not strong enough to call it discovery. We do have enough data to exclude certain mass ranges, however. When you combine our data with D0's (the experiment that did the analysis in TFA), we have enough sensitivity to say that the Higgs, if it is the standard model Higgs (and the lightest SUSY Higgs is sufficiently similar that this holds for it, too), does not have a mass quite close to 170 GeV (which is pretty close to the mass of the top quark, incidentally). http://www-d0.fnal.gov/Run2Physics/WWW/results/prelim/HIGGS/H64/ [fnal.gov]
      • Re:Excuse Me? (Score:5, Informative)

        by AlecC (512609) <aleccawley@gmail.com> on Thursday September 04 2008, @10:09AM (#24874089) Homepage

        Of course they are sharing the raw data. But understanding the raw data means understanding a great deal about the physical structure of the detector. Basically, if you know enough about that, you are part of the CERN team, whether you are physically there or not. Relatively few of the thousands of scientists working "at" CERN are physically there at any time: most spend most of their time connected only electronically. Why do you think the WWW was invented there?

    • by meringuoid (568297) on Thursday September 04 2008, @09:05AM (#24873019)
      TFA notes that 13 out of 20 predicted baryons have been observed, leaving 7 still to be discovered. Surely these will be just as noteworthy as this discovery. Is the LHC the only accelerator capable of creating and observing these remaining baryons?

      Who knows? Perhaps that's why they're yet to be discovered: that we haven't reached the right energies. Well, the LHC will reach far higher energies than anything else on earth. Every time there's been a substantial step up in collision energies, all manner of new particles fall out. That alone makes the LHC favourite to dominate the field for the foreseeable future. That's before you consider the fact that a project of this scale, with absolutely enormous long-term funding, attracts everyone. The best particle physicists in the world are going to be attracted to working on the LHC, or on analysis of the data it produces.

      There'll still be discoveries made elsewhere, but for the headline stuff, watch CERN.

    • by Detritus (11846) on Thursday September 04 2008, @09:17AM (#24873165) Homepage
      Time dilation. Muon decay from cosmic rays is a good example of this.
      • Re: (Score:3, Interesting)

        That puts this particle at about a third of the speed of light.

        No it doesn't, I forgot I'd taken the reciprocal. It puts it at about three times the speed of light. I'd guess the other poster is right, then, and that time dilation prolongs its lifetime.

    • Re: (Score:3, Informative)

      I think it's more accurate to say that it is "starting", and will continue to start for a while. These things don't just turn on, and the LHC has actually been pretty much on-target with the exception of that magnet blowing up.
    • by Candid88 (1292486) on Thursday September 04 2008, @09:23AM (#24873227)

      "with the exception of the Apollo Project"

      Parts of the Apollo projects were put back several time, not to mention ending up costing around double the original estimate despite consisting of less missions than originally planned (cost overruns are almost always closely related to time overruns).

      That's just the nature of big projects (of all types). Nothing specific to do with publicly funded ones, all really big projects commonly take longer than expected. The difference with publicly funded ones is that we all tend to have access to those estimates; whereas private companies tend to just say "it will be done when it's ready" (whilst internally, the estimates are getting put back further and further).

    • by The_Wilschon (782534) on Thursday September 04 2008, @09:51AM (#24873737) Homepage
      Ever since deep inelastic scattering experiments revealed that the proton is not a pointlike charge at sufficiently small electron wavelengths, but rather scatters electrons as if it contained three pointlike (at that scale) charges (+2/3, +2/3, and -1/3), quarks have generally been considered real. Prior to these experiments, there most certainly was ontological debate about quarks. There was also similar debate about atoms for quite some time (see Ernst Mach).