back to article Large Hadron SMASHER: Boffins BLOW OPEN the PENTAQUARK's secrets

Physicists at CERN's Large Hadron Collider say they have discovered the pentaquark – a class of subatomic particle never seen before. "The pentaquark is not just any new particle," said LHCb spokesperson Guy Wilkinson. "It represents a way to aggregate quarks, namely the fundamental constituents of ordinary protons and …

  1. A Non e-mouse Silver badge

    Newton Quote

    There are two interpretations of that Newton quote: One says it was Newton being humble; The other says it was Newton having a dig at Hook.

    Oh - and Newton didn't come up with it first. According to Wikipedia, it can be traced back to at least the 12th century.

    1. This post has been deleted by its author

      1. Destroy All Monsters Silver badge
        Holmes

        Re: Newton Quote

        In 1964, American physicist Murray Gell-Mann made the wild suggestion

        Yup, after having rubbished the idea thoroughly when his colleagues came to talk about this. He always insisted that it was just a "mathematical shortcut" for hadron structure, then ran with the idea when experimental data came in.

        As to the name... from Frank Close's book on the Higgs:

        By the 1960s, experiments with cosmic rays and at accelerators had revealed scores of hadrons. In 1962 Gell-Mann found a way of gathering the mushrooming hadrons into families, most famously containing sets of eight. He poetically named his scheme the "Eightfold Way" after the Buddhist path to truth. The mathematics behind this involved group theory, and the particular group known as SU(3).

        In March 1963 Gell-Mann gave a talk at Columbia University about his new SU(3) theory. A couple of weeks earlier another theorist, Gian Carlo Wick, had given an introductory seminar about SU(3); upon hearing it, Robert Serber realised that in addition to families of eight and ten, which had already been discovered, there should be a basic family of three (as in SU “three”) and, moreover, the octets and tens could be built up as composed of groups of these more basic entities. As Serber later recalled: “The suggestion was immediate; the [hadrons] were not elementary but were made of [what we now call] quarks."

        A fortnight later, Gell-Mann was in town. During lunch at the Faculty Club, Serber explained the idea to him. Gell-Mann asked what the electric charge of the basic trio is. Serber had not looked into this, so Gell-Mann figured it out on a table napkin. The answer turned out to be 2/3 or -1/3 fractions of a proton’s charge, which was an “appalling result”, as no such charges had ever been seen. Gell-Mann mentioned this in the colloquium, and said that such things would be a “strange quirk of nature”. Serber remarked later: “Quirk was jokingly transformed into quark.”

        Finnegan's Wake? Not so much. But so history is made.

        1. Anonymous Coward
          Anonymous Coward

          Re: Newton Quote

          "The answer turned out to be 2/3 or -1/3 fractions of a proton’s charge, which was an “appalling result”, as no such charges had ever been seen."

          It is interesting how because there is so much prior art in physics, early errors or infelicities cannot be readily fixed. Thus cruft accumulates as it does in software.

          The negative sign of the electron charge "worked out OK" in the end (despite it meaning that the original idea of current flow direction was backward) because it later made intuitive sense that the main particles of atoms should be positive or neutral. But the implication of the quark charge is that there would be much cleaner numbers if the electron and proton were -/+3 respectively, thus giving the quarks convenient nonfractional charges.

          Are there other bits of physics where an early decision based on incomplete information has led to awkward numbers?

          1. Anonymous Coward
            Anonymous Coward

            Re: Newton Quote

            "Are there other bits of physics where an early decision based on incomplete information has led to awkward numbers?"

            Aren't most "constants" in physics effectively fudge factors to compensate for the wrong sizing of unit relationships?

            1. Anonymous Coward
              Anonymous Coward

              Re: Newton Quote

              I think Weinberg just decreed everything to be 1.

              Even π.

            2. This post has been deleted by its author

          2. Ken Hagan Gold badge

            Re: Newton Quote

            "Are there other bits of physics where an early decision based on incomplete information has led to awkward numbers?"

            Spin, I suppose, might be more cleanly expressed if fermions had odd spin and bosons had even spin. Beyond that, not much as far as we (yet) know. (Quark color values may yet surprise us.)

            Of course, at a trivial level, all the fundamental constants are horrible non-integral numbers of the units that we devised and standardised before we knew about the constants (length, time and c being the classic example), but I don't think that's what you meant.

          3. Dave 32
            Holmes

            Re: Newton Quote

            So, what's the charge of a Pentaquark? (Yeah, I could look up the charges of the individual quarks that compose it, and add them up, but surely someone has done that already.). What about the spin?

            Dave

            P.S. How long before someone tries to build a computer-like device with these things?

        2. Anonymous Coward
          Anonymous Coward

          Re: Newton Quote

          "Finnegan's Wake? Not so much. But so history is made"

          Well, yes. But some of us encountered the levée of the Finnegans before quarks became sufficiently mainstream to read about them1. It was a natural assumption that Gell-Mann, who was known to be widely read, very interested in etymology and linguistics, and a stickler for correct pronunciation of non-English words, would be familiar with Finnegans Wake and so named quarks on that basis. "Quirk was jokingly transformed into quark" - why if not because "three quarks for Musther Mark?"

          There is no proof either way. Let's say that the Joyce theory of quark naming is in a superposition of states.

          1 [When I started at U one of our lecturers mentioned in passing that someone had just announced experimental evidence that protons had structure, but didn't use the q-word. Nor did Bjorken and Feynman. The history of physics tends to get presented as an unbroken story, but it is a lot more complicated than that.]

    2. asdf Silver badge

      Re: Newton Quote

      Hooke was beyond ignorant in this regard. If you are going to throw intellectual poop (something he did a lot of in his lifetime) its probably best to avoid targeting the greatest scientist who ever lived.

  2. PleebSmash
    Boffin

    never?

    When are we going to see stable "atoms"/molecules/compounds made from unusual quark configurations?

    1. frank ly

      Re: never?

      I don't think we will. These states of matter need enourmous amounts of energy to create them, such as by smashing protons together at nearly the speed of light. They are short lived arrangements that quickly decay to more stable configurations. They can give information about how things work and what the numbers/relationships are, which does help us to understand the 'ordinary' matter better.

      1. PleebSmash

        Re: never?

        It could be like the "island of stability". Very fast decay for most pentaquark/etc based compounds, with a mythical stable configuration yet to be found.

        1. DougS Silver badge

          Re: never?

          Perhaps dark matter, if it exists, is stable neutral particles made up from more than three quarks.

          1. Anonymous Coward
            Anonymous Coward

            Re: never?

            "Perhaps dark matter, if it exists, is stable neutral particles made up from more than three quarks."

            Any particle made from quarks is surely going to interact with atomic nuclei, just like neutrons do? It will feel the strong force.

    2. Captain DaFt

      Re: never?

      "When are we going to see stable "atoms"/molecules/compounds made from unusual quark configurations?"

      May already have.

      This is an alternate structure of the pentaquark; a meson particle (one quark and one antiquark) and a baryon (three quarks) weakly bonded together.

  3. adnim Silver badge
    Joke

    Five

    sided quarks, cool.

    As for Gell-Mann ... "If I have seen further than others, it is because I am surrounded by dwarfs standing on the shoulders of giants."

    1. Paul Crawford Silver badge

      Re: Five

      "If I have seen further than others, it is because I am surrounded by dwarfs standing on the shoulders of giants was defenestrated from a tall building and survived"

      1. Chris Miller

        "If I have seen less far than other men, it is because dwarfs were standing on my shoulders."

    2. Ken Hagan Gold badge

      Re: Five

      "If I have seen further than others, it is because I was looking the wrong way and got lucky."

      1. Martin Budden Bronze badge

        Re: Five

        "If I have seen further than others, it is because I've got the binoculars."

  4. Anonymous Coward
    Anonymous Coward

    How would you know you were surrounded by dwarfs?

    1. Paul Crawford Silver badge

      Easy - they are the ones signing about gold and carrying axes.

      1. Anonymous Coward
        Anonymous Coward

        "Easy - they are the ones signing about gold and carrying axes."

        Presumably all that hammering had made them all deaf.

  5. hatti

    For quarks sake!

    "More precisely, the states must be formed of two up quarks, one down quark, and one charm quark and one anti-charm quark."

    As is often witnessed in a game of Kerplunk.

  6. wolfetone Silver badge
    Joke

    Finally we can see the smallest things in the universe.

    But we still can't come up with a reason as to why Kim Kardashian is a thing.

    1. Anonymous Coward
      Anonymous Coward

      "But we still can't come up with a reason as to why Kim Kardashian is a thing."

      Put it like this: it isn't what stands on her shoulders, more what hangs off them.

      1. Dave 32
        Coat

        Re: "But we still can't come up with a reason as to why Kim Kardashian is a thing."

        Aieeee! Have we developed a analog to Godwin's Law? When someone mentions Kim Kardashian, the usefulness of a discussion has come to an end.

        Dave

        P.S. Just please don't name that law after me! Ack! I don't want my name, or anything else, around her.

        1. Anonymous Coward
          Anonymous Coward

          Re: "But we still can't come up with a reason as to why Kim Kardashian is a thing."

          "When someone mentions Kim Kardashian, the usefulness of a discussion has come to an end."

          I'm not sure why. As a genuine icon of the Facebook era, famous for being notorious and having built a rather successful career out of it, there are quite a number of aspects of contemporary culture that she relates to. Terry Pratchett made a few acute observations on the phenomenon in Unseen Academicals.

          On the other hand pretending to be "above" her in the interests of cultural distancing and the reinforcement of claimed superiority is very much a thing, and perhaps we should just refer to doing that as 32's Law (Godwin's Law isn't called Mike's Law.)

  7. Bluto Nash
    Facepalm

    My brain hurts.

    1. Anonymous Coward
      Anonymous Coward

      But the brain has no pain receptors?

      1. Ken Hagan Gold badge

        "But the brain has no pain receptors?"

        But it sits on the shoulders of a very large number of them.

      2. Anonymous Coward
        Anonymous Coward

        Re: the brain has no pain receptors?

        Doesn't need any: it might just tell you you are in pain regardless of what is actually happening, which would be quite good enough. :-)

  8. Ugotta B. Kiddingme Silver badge

    anti-charm quark?

    Is that like the loutish brother-in-law who pees on your front lawn after drinking all your beer because he dropped in, unannounced, at an inopportune time?

  9. Michael Dunn
    Joke

    This Penta thingy

    Has the LHC found evidence for the existence of Satan?

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