back to article LHC finds a new and very charming particle: the Xicc++ baryon

What happens if you get two charm quarks together in one baryon? Something four times as heavy as a proton that can help the world understand the strong nuclear force, according to boffins at the Large Hadron Collider. Last week, CERN announced the first “unambiguous” observation of a particle comprising the two charm quarks …

  1. Crisp

    1.7 femtobarns?

    That's a pretty small barn.

    1. Anonymous Coward
      Anonymous Coward

      Re: 1.7 femtobarns?

      Yup but with the exploding costs of real estate around Geneva that's about all a nuclear scientist can afford these days.

    2. Anonymous Coward
      Anonymous Coward

      Re: 1.7 femtobarns?

      I think they have it wrong; the luminosity should be 1.7 inverse femtobarns, which is a pretty big number. A barn is a measure of particle cross-section for a collision; a femtobarn is 10-15 barns; 1.7 inverse femtobarns is therefore 1.7 * 1015 collisions per particle cross section, which is an awful lot.

    3. maffski

      Re: 1.7 femtobarns?

      No, it's almost two pretty small barns.

      1. Anonymous Coward
        Anonymous Coward

        Re: 1.7 femtobarns?

        Only imperial stormtroopers can be so precise as to hit that.

        1. Anonymous Coward
          Anonymous Coward

          Re: 1.7 femtobarns?

          You wouldn't say that after you saw how they fire every time the heroes try to escape... they can't hit a slow moving robot... but, oh well, hitting a Java vehicle should be easier, it's quite larger than a barn... probably Obi Wan meant "they just hit the vehicle, not everything in a ten miles radius..."

          1. Destroy All Monsters Silver badge

            Re: 1.7 femtobarns?

            hitting a Java vehicle should be easier, it's quite larger than a barn

            It's probably a Java Enterprise Edition vehicle then.

  2. Anonymous Coward
    Anonymous Coward

    Awe

    I "read" this article and frankly, haven"t a clue what it in on about. I am honestly in awe of these people that understand this stuff.

    I would offer them a beer but I suppose they would be too busy looking for the next quantamy quarky higgs thingy to come along.

    The thing is, how do they know to look for these things if they don't know they exist?

    Gentlemen, seriously, I take my hat off to you. Even if you do make my brain hurt!

    Cheers… Ishy

    1. MrDamage Silver badge

      Re: Awe

      Go ahead and offer them a beer. Eventually one will spill it on the control panel, and we'll end up with a varient of D.A's Limited Improbability Engine, which some will then connect to a cup of tea to make an Unlimited Improbability Engine.

      1. The First Dave
        Headmaster

        Re: Awe

        "Finite" and "Infinite" improbability engines, actually.

    2. Anonymous Coward
      Anonymous Coward

      "how do they know to look for these things if they don't know they exist?"

      Sometimes they know they probably exist, and how they should look: "something the researchers say is predicted by the Standard Model and has been sought for many years" (caps mine, as it should be).

      Sometimes your data show something unexpected - and you get busy understanding why.

    3. Chris G

      Re: Awe

      Most good scientists appreciate the value of a beer or several it can ,stimulate different thought processes and discussio. Humans and elephants are evolved to cope with alcohol, drunken elephants like to pull down trees and socialise, drunken scientists like to pull down trees (or blow things up) socialise and experiment.

      I'll there are a few discoveries that would never have happened if beer had ever been invented.

      1. werdsmith Silver badge

        Re: Awe

        Top physicists and scientists > Rock Stars > footballers.

        1. Anonymous Coward
          Anonymous Coward

          Re: Awe

          Top physicists and scientists > Rock Stars > footballers

          Top physicists and scientists > Lots and lots of other people > Rock Stars > footballers

          1. Gotno iShit Wantno iShit

            Re: Awe

            Top physicists and scientists > Lots and lots of other people > Rock Stars > footballers

            Top physicists and scientists > Lots and lots of other people > Rock Stars > lice > footballers

      2. Anonymous Coward
        Anonymous Coward

        Re: Awe

        Actually, some appreciate the virtue of old Cognac...

        https://www.quantamagazine.org/supersymmetry-bet-settled-with-cognac-20160822/

      3. Ugotta B. Kiddingme

        Re: "a few discoveries that would never have happened if beer hadn't been invented"

        ... giving rise to the phrase "Hold my Nobel Prize and watch this!"

    4. Tom 7

      Re: Awe

      "I would offer them a beer but I suppose they would be too busy looking for the next quantamy quarky higgs thingy to come along."

      Its very important to remember the brain is a complicated system and like all complicated systems it can get locked in unideal states. This is cured by annealing and the brain is best annealed with beer and similarly annealing company.

    5. Rocket
      Boffin

      Re: Awe

      - I "read" this article and frankly, haven"t a clue what it's on about.

      - I am honestly in awe of these people that understand this stuff.

      I'm definitely putting Quantum Dynamics as my religion / "belief system" on the next census.

      At least scientists can prove what they believe even if the rest of us can't understand it.

      btw - They got me confused with scientologist last time ;-)

      1. David Nash Silver badge

        Re: Awe

        "I'm definitely putting Quantum Dynamics as my religion / "belief system" on the next census."

        Can something be a religion if there is evidence to support it's claims?

        1. Anonymous Coward
          Anonymous Coward

          Re: Awe

          "Can something be a religion if there is evidence to support it's claims?"

          Of course. It just can't be a supernatural religion.

      2. Charlie Clark Silver badge
        Coat

        Re: Awe

        I'm definitely putting Quantum Dynamics as my religion / "belief system" on the next census

        If you definitely believe in quantum dynamics, you probably don't!

        Mine's the one with "Favourite Quantum Dynamic Quotes and Other Animals" in the pocket.

    6. bazza Silver badge

      Re: Awe

      I would offer them a beer but I suppose they would be too busy looking for the next quantamy quarky higgs thingy to come along.

      Nope, beer works well no matter what, offer away!

      In fact beer was the inspiration for the bubble chamber, a now sadly obsolete detector type that used vast quantities of superheated liquid hydrogen to form bubbles around the tracks of particles which were then photographed.

    7. stephanh

      Re: Awe

      @ Ishtiaq

      Actually it is not that complicated, it is more that the terminology is somewhat daunting, if you are unfamiliar with the whole "particle zoo".

      * Quarks and anti-quarks are the fundamental particles which carry the strong nuclear force. There are many types of quarks (and each has its corresponding anti-quark) but they are usually categorized in generations. Quarks from the first generation are the lightest, and each generation gets progressively heavier (just like Americans). Unlike Americans, the heavier generations tend to decay very fast into the lighter ones.

      * A hadron is a compound particle made of multiple quarks or anti-quarks.

      * A baryon is a hadron made of three quarks. The most familiar baryons are protons and neutrons, which make up most of the mass of your beer. Protons and neutrons are made of the lightest (first) generation quarks, which is fortunate otherwise you would have to finish your beer within a few femto-seconds before its constituent quarks would decay.

      * A meson is a hadron made of exactly one quark and one anti-quark. They tend to have short and eventful lives, since the quark and anti-quark want to annihilate each other. (However, the quark and anti-quark are not necessarily, ahum, "compatible").

      * Pions and kaons are particular types of mesons. I'll spare you the details.

      * A Lambda baryon is a baryon which has one quark from the heavier generations, and two first-generation quarks.

      * A Xi baryon is a baryon which has two quarks from the heavier generations, and one first-generation quark.

      So the Xi cc++ baryon consists, being a baryon, of three quarks. One up-quark, which is a bog-standard first-generation quark very common in your beer, and *two* charm quarks, which are heavy second-generation quarks. (The cc means "two charms".) It then decays into a Lambda baryon with only one charm quark, and some mesons to make up for the various conversation law.

      1. imanidiot Silver badge

        Re: Awe

        Thanks StephanH, that was very informative.

        What do the ++ in Xi cc++ denote? Is that the up-quark or the spin of the charm quarks or something?

        1. stephanh

          Re: Awe

          The ++ refers to its electric charge, which is twice the elementary charge. ( i.e. charge of a proton)

  3. Anonymous Coward
    Anonymous Coward

    I would offer them a beer but I suppose they would be too busy looking for the next quantamy quarky higgs thingy to come along.

    Nonsense - give them that beer. I find having a beer with colleagues is a quicker route to solving problems than trying to hammer it out in a too brightly lit office with not enough oxygen and too many suits and other distractions around. The only thing missing is a white board.

    At least, that's how I am going to try expensing pub visits :).

    1. Sir Runcible Spoon
      Thumb Up

      A pub with a whiteboard - OMG!!! What a fantastic idea :D

      1. Andytug

        Hmmm...except that....

        the time for said whiteboard to be covered in CDC graffiti would be measured in microseconds........

      2. staggers

        Careful, Sir Runcible

        If they know you can count they'll have you chalking up all night.

        Not that being a physicist means you can count, of course. Too human.

        At least physics is capable of being explained to the layman such that the gist of something can be grasped. J. G. made a certain cat the most famous thing in quantum physics, as far as the layman is concerned. And a good job he did too.

        But explaining, for example, how the solution to FLT was finally arrived at, well I read the book, and it's still a fog to me. I had a close relative who was a mathematician. He was always trying to explain things. You see, I am genuinely interested, but I just can't get my head around it.

        Is there out there such a thing as a very abstract 'overview' of what all these different things are 'for' in their own right?

        I'm starting to think that they walk among us, they look like us, but they are not us! Or am I just thick?!

        1. Anonymous Coward
          Anonymous Coward

          Re: Careful, Sir Runcible

          "Not that being a physicist means you can count, of course. Too human."

          Actually counting is not inherent in people beyond about 3 - numbers require teaching just as does integral calculus, we just tend to be younger when it happens. Jackdaws seem to be innately better at counting than people.

          Being a physicist means you lose count because you've just thought of an interesting idea about dart trajectory and are too busy thinking about it, just as my grandfather put a lot of effort into making absolutely perfectly balanced darts, including home designed flights - but didn't have the motor skills to be really good at it.

        2. Sir Runcible Spoon

          Re: Careful, Sir Runcible

          "If they know you can count they'll have you chalking up all night."

          That was how I got away with being in the pub on my own from about 14 :)

  4. dan1980

    ". . . observation of a particle comprising the two charm quarks and one up quark – something the researchers say is predicted by the standard model . . ."

    Provided the constituents add to a whole charge, are there any 2 or 3 quark particles that are not predicted?

    1. Nick Ryan Silver badge

      From what I understand, it's just a case of arranging the basic building components into non-repeating, i.e. elementary groups. Given this there's a nice grid of particles that could/should exist as there's quite a finite set of possibilities.

      Until of course some bugger finds a way of breaking the lower level components into parts to see how they're made up and then predicts some new basic building blocks to play with.

      (I'm not a particle physicist by a long way, but know enough to appreciate some of the issues without my mind imploding)

    2. Anonymous Coward
      Anonymous Coward

      "are there any 2 or 3 quark particles that are not predicted?"

      If so, the Standard Model would suffer a blow - and new models would be needed to explain those particles.

      Anyway, the electromagnetic charge is not the only limit, there are other "exclusion" requirement regarding the quantum states (see Pauli exclusion principle).

      1. Daedalus

        Re: "are there any 2 or 3 quark particles that are not predicted?"

        Since all quarks have a charge that is a multiple of 1/3, any three-quark particle has a whole number charge. For the "familiar" quarks, all the combinations have been seen and catalogued. We've found triple-up, triple-down, and triple-strange, for instance. The only barrier to seeing triple-charm, top, or bottom is the energy needed to make them, and the probability that they will decay very quickly, making them hard to see. In fact you "see" them by recognizing their decay products, which have to be predicted ahead of time. That's harder that "predicting" the existence of the particles themselves.

        The only 2-quark particles that cannot exist are those where a quark is paired with another one, and not an anti-quark as in a meson. For instance, up/up, up/down, are illegal in the Standard Model, but up/anti-up is just the familiar neutral pi-meson.

        1. dan1980

          Re: "are there any 2 or 3 quark particles that are not predicted?"

          @Daedalus

          "Since all quarks have a charge that is a multiple of 1/3, any three-quark particle has a whole number charge."

          You mention the necessity of mesons having one quark and one anti-quark but skip that baryons are the opposite: they must have ONLY quarks or ONLY anti-quarks.

          For example, if you start with a strange (-1/3) and an anti-charm (-2/3), you have -1 charge but no third quark or anti-quark you can add will leave the resulting 3-quark particle with a whole charge.

          NOW, it is my understanding that the requirement of a whole charge is not what governs the combination of quarks but is instead 'merely' a result of some deeper rule. But that is a layman's understanding and when words like 'gauge' and 'symmetry' and 'iso-spin' and 'group' get thrown around, Dan is sorely out of his depth.

          Of course, when you come to the charge of an electron being exactly (so far as is known) the same as that of a proton, things get profounding amazing and I am in awe of this wonderful universe (and those unravelling its secrets). But even then, if there is some 'grand unified theory' then there are real connections between the forces at play and so this is all, perhaps, to be expected.

          Hence using the result of whole charges as a rule for me : )

          The question I suppose at the heart of my earlier question is: do these underlying rules of combination preclude any combinations that would otherwise create a particle with a whole charge multiple?

  5. Winkypop Silver badge
    Thumb Up

    And I thought school was a forced day care centre.

    These guys and girls were the ones listening and learning.

    A+

    1. Anonymous Coward
      Anonymous Coward

      Re: And I thought school was a forced day care centre.

      P J O'Rourke once described South Korea as a country full of people who stayed in on Friday evening to do their school homework.

      Figures.

  6. Anonymous Coward
    Anonymous Coward

    The XICC++ baryon?

    Clearly this baryon has class, unlike the XiCC baryon.

    1. Tom 7

      Re: The XICC++ baryon?

      Baryons with inheritance? Perhaps quantum effects are the kids fighting over the assets.

      1. Anonymous Coward
        Anonymous Coward

        Re: The XICC++ baryon?

        Yes, but the problem is multiple inheritance. All because of that old up quark who becomes attached to two charming ones in the heat of the collision...

        1. allthecoolshortnamesweretaken

          Re: The XICC++ baryon?

          Is there a posh quark?

          1. Andytug
            Joke

            Re: The XICC++ baryon?

            No......a quark is what a posh duck says!

          2. Anonymous Coward
            Anonymous Coward

            Re: The XICC++ baryon?

            "Is there a posh quark?"

            Only when there's a Becks quark. They appear spontaniously together whenever large numbers of photons are emitted by a photographic flash.

  7. Paul Herber Silver badge

    XICC - how do you pronounce that?

    XICC = chic?

    Chic++

    1. molletts

      Re: XICC - how do you pronounce that?

      I must admit that I read it as "Xi (as in the Greek character Ξ/ξ)-double-charm-two-plus" but I'm no expert on this kind of stuff.

      That said, "chic-plus-plus" has a certain ring to it (and is a darn sight easier to say). Doesn't sound sufficiently particley to me, though. New programming language with a focus on style, perhaps?

      1. Anonymous Coward
        Anonymous Coward

        Re: XICC - how do you pronounce that?

        But Nature is functional, not object-oriented.

  8. Destroy All Monsters Silver badge
    Headmaster

    “In contrast to other baryons, in which the three quarks perform an elaborate dance around each other, a doubly heavy baryon is expected to act like a planetary system, where the two heavy quarks play the role of heavy stars orbiting one around the other, with the lighter quark orbiting around this binary system”.

    This is apparently not the right image to have in mind.

    Check this nice stack overflow entry: How (or when) do gluons change the color of a quark?

    Why does the universe infrastructure perform these crazy girations with complex probabilities tacked onto everything? Lattice QCD simulations of a simple nuclean on 16×16×16×32 grids eat CPU cycles raw.

  9. Sir Runcible Spoon

    When does it all go wrong?

    Is there an energy level for these types of collisions where the Standard Model predicts something drastic happens?

    1. Destroy All Monsters Silver badge
      Holmes

      Re: When does it all go wrong?

      No.

      The Standard Model indeed predicts nothing drastic will happen anywhere, it is regarded as a "low energy" approximation of .... something.

      Which may be everything.

      The moving of the goalposts for the energy scale at which supersymmetric particles are supposed to appear is symptomatic.

      The idea is setting in that "the big desert" hypotheses may well hold: Nothing drastic happens up to energy scales so high as to be unattainable except by God itself.

      Weinberg on the Desert, Seiberg on QFT: Posted on December 9, 2014 by woit

  10. Richard Gray 1
    Pint

    Quote of the day

    If I could remember the names of all these particles, I'd be a botanist.

    -Enrico Fermi

    1. Destroy All Monsters Silver badge
      Holmes

      Re: Quote of the day

      I prefer Fermi's warning to Louis Slotin to stop monkeying around in an agile way with a Plutonium core:

      “Keep doing that experiment that way and you’ll be dead within a year.”

      Slotin was dead within a year.

      Never disregard an Italian's advice when death is on the line.

  11. Chris Hainey

    The 2017 Proton Billiards season has started well then

  12. J.G.Harston Silver badge

    Xicc++

    Yer wot? It's about time physists sat down and built a proper structured naming scheme for all this nonsense.

    1. stephanh

      Re: Xicc++

      Well, it kind of already is.

      You need to parse the name like this: Xi ; cc ; ++

      * "Xi" (or Ξ) means it is a baryon consisting of two heavy quarks and one normal one.

      * "cc" means the heavy quarks are two "charm" quarks ("cc" = "charm charm")

      * "++" means it has twice the charge of a proton. From that we can infer that the remaining "normal" quark is an up-quark. (charm and up-quarks both have charge +2/3).

      Of course a simpler naming scheme (which is also sometimes used) is to just list the component quarks. Then this would be an ucc (up/charm/charm) baryon; a proton is then an uud baryon (up/up/down) and a neutron is an udd (up/down/down) baryon.

  13. jeffycutt

    WHAT EVRYONE IS MISSING ABOUT THIS DISCOVERY:

    Excluding all of the particles that exist for "an instant" (which include OTHER QUARK pairs) ALL of the elements on the periodic table that stay existing (mostly) are made of Baryons which are the Proton and the Neutron (which are made of these "stay existing" quarks in TOP/DOWN configurations). The pair that make the atom are known nucleons.

    Mush up nucleons together you start going thru the periodic table of elements from hydrogen to gold.. Meanwhile electrons are all packed in there too. Here's the kicker...

    When the size of your massive "nucleon ball" go beyond the range of the "first" election shell range then you get MASSIVE RADIATION because the toothpaste is literally out of the tube and cant get reeled back to be stable (the neutron proton pair fall apart and flying neutrons are a big nono). Now were at plutonium, uranium etc etc... it seems like nothing can be heavier/stronger metal unless its radioactive right?? What if there is something besides the neutron and proton?

    That's Xi-cc++ !! If you can have a nucleon pair that's 4x as dense im pretty sure its safe to assume the electrons are packed in too in a way that geometrically makes sense because universe and math tend to do that kind of stuff. VLOIA!! super exotic metals of magical properties can exist and NOT be radioactive because they are configured to "fit tighter". The possibilities become limitless. 'Indestructible materials' (to universe standards)

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