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Science

LHC Discovers Pentaquark Particles 95

Posted by Soulskill from the quantum-party-of-five dept.
mrspoonsi sends news that researchers running experiments at the Large Hadron Collider have published findings confirming the existence of pentaquark particles, first predicted in the 1960s by Murray Gell Mann and George Zweig. The particles consist of five quarks bound together. Further research will examine exactly how this binding works. Previous experiments had measured only the so-called mass distribution where a statistical peak may appear against the background "noise" - the possible signature of a novel particle. But the collider enabled researchers to look at the data from additional perspectives, namely the four angles defined by the different directions of travel taken by particles within LHCb. "We are transforming this problem from a one-dimensional to a five dimensional one... we are able to describe everything that happens in the decay," said Dr. Koppenburg, who first saw a signal begin to emerge in 2012. "There is no way that what we see could be due to something else other than the addition of a new particle that was not observed before."
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LHC Discovers Pentaquark Particles More

LHC Discovers Pentaquark Particles

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  • Gillette (Score:5, Funny)

    by Anonymous Coward on Tuesday July 14, 2015 @03:26PM (#50111045)

    Gillette: Fuck it, we're doing five quarks!!

  • I for one (Score:1)

    by Anonymous Coward

    I for one welcome our exotic matter overlords.

    • Re: (Score:1)

      by Anonymous Coward

      With a crowbar in hand.

    • This is not the first time that someone has claimed to observe pentaquarks. I'd suggest holding off the welcome until this result is confirmed by several other experiments. Last time there was a confusing mixture of confirmations and non-confirmations until the consensus emerged that there was no evidence to support the existence of pentaquarks.

  • This is why physics is the king of the sciences (Score:5, Insightful)

    by Crashmarik ( 635988 ) on Tuesday July 14, 2015 @03:42PM (#50111189)

    When the mathematics is so powerful that it can make accurate predictions far in advance of their ability to be verified, you know you are connecting with the fundamental mechanisms that drive the universe.

    • Re:This is why physics is the king of the sciences (Score:5, Insightful)

      by CrimsonAvenger ( 580665 ) on Tuesday July 14, 2015 @03:44PM (#50111195)

      Either that, or you're not the guy who made the incorrect prediction 50 years back....

    • Re:This is why physics is the king of the sciences (Score:5, Informative)

      by ConceptJunkie ( 24823 ) on Tuesday July 14, 2015 @04:08PM (#50111407) Homepage Journal

      General Relativity is a shining example of this, and the Standard Model is even more so. These theories are among the most accurate predictors of new discoveries, sometimes ridiculously so.

      Meanwhile, String Theory is still kicking around, getting more and more complex, but coming up with very little in the way of prediction. I'm not busting on it... I keep up with the latest work (as much as a non-expert can anyway) and find it fascinating (and/or incomprehensible).

      We are definitely tapping into something real, but whether or not it's fundamental is another question entirely. Newton seemed fundamental, but wasn't. Einstein seems fundamental, but might not be. It seems like there's usually another layer of reality below the one which seems to be fundamental. But everything we uncover is fascinating.

      I guess what I'm trying to say is, "Science is cool".

      • We are definitely tapping into something real, but whether or not it's fundamental is another question entirely. Newton seemed fundamental, but wasn't. Einstein seems fundamental, but might not be. It seems like there's usually another layer of reality below the one which seems to be fundamental.

        We haven't even reached turtles yet.

      • Re:This is why physics is the king of the sciences (Score:5, Insightful)

        by Jason Levine ( 196982 ) on Tuesday July 14, 2015 @04:20PM (#50111517) Homepage

        Just to tap into another great scientific discovery, the New Horizons mission is a great example of this also. Nine years ago, scientists had to plan a route and engineers had to design systems. All of this had to be extremely precise. New Horizons had a 100 km by 150 km window of space that it had to be in within 100 seconds. If it was out of this area, the photos would return blank space. While we won't know if it hit the target until the photos come back late tonight/early tomorrow, it looks like they hit the mark. That's planning a route 9 years out and 5 billion km away. That took some serious understanding of orbital velocity to accomplish. One tiny mistake and New Horizons would have wound up far away from Pluto.

        • New Horizons had a 100 km by 150 km window of space that it had to be in within 100 seconds. If it was out of this area, the photos would return blank space. While we won't know if it hit the target until the photos come back late tonight/early tomorrow, it looks like they hit the mark. That's planning a route 9 years out and 5 billion km away.

          You left out, as Paul Harvey says, the rest of the story.

          While they planned the route fourteen years ago, they've spent the last nine years (since launch) analyzing the spacecraft's current trajectory and making mid course corrections as needed to ensure that New Horizons hit the window. If they hadn't done so, less than forty minutes after launch New Horizons would have been doomed to miss Pluto entirely. (The booster ended up performing a little 'hot' - when the final stage was discarded, it was actually going too fast.)

          Don't get me wrong, it's still a fantastic achievement that all they needed was 20 m/s (give or take a little) of course correction - but the fact remains that New Horizons wasn't passively ballistic, it was actively flown.

      • Re: (Score:2)

        by bsolar ( 1176767 )

        It seems like there's usually another layer of reality below the one which seems to be fundamental.

        Nice to know that the fundamental theorem of software engineering applies to the design of the universe too.

      • Great points, and I fully agree, but I want to go a bit further.

        General Relativity is amazing and wonderful, but I think we can safely say it's not complete or fundamental. Aside from dark matter, the insides of black holes, and quantum effects, it doesn't provide any mechanism for curved spacetime. As much praise as I think Einstein and GR deserve, too often I see and hear people treat it as the ultimate truth of the universe, particularly curved spacetime. I'm somewhat skeptical of String Theory, but I e

    • Re:This is why physics is the king of the sciences (Score:4, Interesting)

      by known_coward_69 ( 4151743 ) on Tuesday July 14, 2015 @04:09PM (#50111423)
      to be fair they have the math worked out for dozens of variants of different theories and need the experiments to confirm which one was right. the original estimates for the higgs boson were all over the place and depending on the energy predicted it would have meant a single dimension, multi-dimensions and lots of other possibilities.

    • some would argue mathematics is king of the sciences

      • Mathematics isn't a science any more than fashion is a science. They are just off the scales at different ends.

      • Most mathematicians would dispute the point and consider the title belittling.

      • some would argue mathematics is king of the sciences

        Mathematics is not a science. It is a language used to describe scientific principles and theories.

        • Because you say so? Oxford dictionary disagrees with you.

          • Because you say so? Oxford dictionary disagrees with you.

            The "study" of mathematics is a science in the broad sense, just like the "study" of theology is also a science. But mathematics itself, particularly as used in the context of this article, is a descriptive language.

    • Re: (Score:1)

      by shoor ( 33382 )

      I don't so much disagree as consider it a narrow viewpoint. Darwin's Theory of the Origin Of Species by Natural Selection was pretty damn regal in my opinion, and, I daresay, has even influenced the thinking of many physicists. Computer Science has had a big influence too. (I think Computers are the 'steam engines' of the 20th Century in the sense that physicists learned about thermodynamics in the 19th Century from studying the steam engine, which led to all kinds of stuff, and studying what computers c

  • so this must the be the Satan Particle.

  • http://i.imgur.com/lkgpKG0.png [imgur.com] (stealing someone else's joke but still made me laugh....)
  • So what's the net charge on a pentaquark ?

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

      +1.

      • Re:+2/3, -1/3 (Score:5, Funny)

        by omnichad ( 1198475 ) on Tuesday July 14, 2015 @04:17PM (#50111497) Homepage

        two up quarks, one down quark

        Still haven't discovered the Konami quark then, yet?

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

        The states also require that there be both bofa and updog.

      • Re:+2/3, -1/3 (Score:4, Informative)

        by ClickOnThis ( 137803 ) on Tuesday July 14, 2015 @04:28PM (#50111591) Journal

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

        +1.

        In detail...
        up quark: +2/3
        down quark: -1/3
        charm quark: +2/3
        anti-charm quark: -2/3

        2/3 + 2/3 - 1/3 + 2/3 - 2/3 = +1.

        • Re:+2/3, -1/3 (Score:4, Interesting)

          by bugs2squash ( 1132591 ) on Tuesday July 14, 2015 @04:45PM (#50111713)
          Thanks - so why don't the charm and the anti-charm go "poof" ?

          • Re:+2/3, -1/3 (Score:4, Insightful)

            by ClickOnThis ( 137803 ) on Tuesday July 14, 2015 @05:00PM (#50111825) Journal

            Thanks - so why don't the charm and the anti-charm go "poof" ?

            No doubt they do. Many exotic particles don't have long lifetimes. I'm not sure what the pentaquark's lifetime is.

            The J/psi meson, [wikipedia.org] which consists of a charm-anticharm pair, lives for about 7.2 x 10^-21 s.

          • Re: (Score:2)

            by habig ( 12787 )

            Thanks - so why don't the charm and the anti-charm go "poof" ?

            They do, sort of: this thing doesn't last long at all.

            Consider a much more common particle, the neutral pi meson: just two quarks: quark/antiquark pairs of several possible flavors. Also doesn't last long (8e-17s), but extremely well studied.,

          • IANAP but I would guess that the quantum numbers add up such that it does look like the charm and anti-charm quark went "poof" in some respects (like color charge, I imagine, otherwise I don't see how the chromodynamics can work out with a five-particle system; the color of the anti-charm must be opposite that of the charm, whatever it is, and the remaining three red, green, and blue, respectively, to get a white particle as required by QCD), but left over residual features (like spin and electric charge) i

          • Thanks - so why don't the charm and the anti-charm go "poof" ?

            They might not be antiparticles of each other, as they might differ in color charge [wikipedia.org].

            • Thanks - so why don't the charm and the anti-charm go "poof" ?

              They might not be antiparticles of each other, as they might differ in color charge [wikipedia.org].

              I think that would violate color confinement [wikipedia.org] because the resulting pentaquark would have a net color.

              • Re:+2/3, -1/3 (Score:5, Informative)

                by Guy Harris ( 3803 ) <guy@alum.mit.edu> on Tuesday July 14, 2015 @05:47PM (#50112187)

                Thanks - so why don't the charm and the anti-charm go "poof" ?

                They might not be antiparticles of each other, as they might differ in color charge [wikipedia.org].

                I think that would violate color confinement [wikipedia.org] because the resulting pentaquark would have a net color.

                Red up quark, blue down quark, blue charmed quark, green up quark, antiblue anti-charmed quark. Net color = R+B+B+G-B = R+B+G = colorless. (Shamelessly lifted from the "2015 LHCb results" section of the Wikipedia page for the pentaquark [wikipedia.org].)

                • Ah! Thanks for that. After I posted, I wondered if that was possible.

                • Thanks - so why don't the charm and the anti-charm go "poof" ?

                  They might not be antiparticles of each other, as they might differ in color charge [wikipedia.org].

                  I think that would violate color confinement [wikipedia.org] because the resulting pentaquark would have a net color.

                  Red up quark, blue down quark, blue charmed quark, green up quark, antiblue anti-charmed quark. Net color = R+B+B+G-B = R+B+G = colorless. (Shamelessly lifted from the "2015 LHCb results" section of the Wikipedia page for the pentaquark [wikipedia.org].)

                  Wait ... the two charmed quarks you mentioned are in fact anti-particles.

                  Did you mean to swap the blue and green on the charmed and up quarks? That would in fact make the charmed quarks not anti-particles to each other. I'm not sure that's even possible (I'm not an expert on the standard model, let alone pentaquarks) but I assume it would at least not violate Pauli exclusion (because the two up-quarks aren't the same color.)

  • Any other day this would be so cool for science geeks. But today we're all just waiting for the photos of Pluto to come streaming back to us.

  • Please Speak English (Score:1)

    by Anonymous Coward

    Observations of exotic structures in the J/p channel, that we refer to as pentaquark-charmonium states, in 0bJ/Kp decays are presented. The data sample corresponds to an integrated luminosity of 3/fb acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis is performed on the three-body final-state that reproduces the two-body mass and angular distributions. To obtain a satisfactory fit of the structures seen in the J/p mass spectrum, it is necessary to include two Breit-Wigner

    • Not gobblygook at all, it is perfectly understandable with even undergraduate level knowledge of particle physics.

      Layman's articles targeting high school or less education on this abound, you can find them with search engine.

      • Re: (Score:2, Insightful)

        by Anonymous Coward

        You have stumbled onto the true problem with ignorance: The ignorant refuse to believe they're actually ignorant.

        And the educated know enough to understand the limits of their knowledge and acknowledge their own ignorance, perhaps too much.

    • You aren't the target audience for the scientific article. That's what the press release [web.cern.ch] is for. Abstracts are not the same as introductions. They are necessarily succinct, to the point where use of jargon is required.

  • What's happened to Slashdot? :) (Score:5, Funny)

    by Xtifr ( 1323 ) on Tuesday July 14, 2015 @06:09PM (#50112371) Homepage

    Ok, three links, one to an actual pre-pub paper, one to CERN's official press release, and one to a reputable news source? What's wrong with this submitter? Don't you know that Slashdot links are supposed to go to some random bozo's blog, where he rants about the political repercussions of a discovery like this, and how it will affect free software/NSA spying/Sharia law/the Lizard people, all with no useful links to any hard data anywhere, but hundreds of ads? :)

    Seriously, I've been expecting this since the recent announcement of a possible tetraquark particle, but I certainly didn't expect it this soon. Very cool.

  • The harder you hit things, the more pieces they break into.

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