LHCb Confirms Existence of Exotic Hadrons 99
An anonymous reader sends this news from CERN:
"The Large Hadron Collider beauty (LHCb) collaboration today announced results that confirm the existence of exotic hadrons – a type of matter that cannot be classified within the traditional quark model. Hadrons are subatomic particles that can take part in the strong interaction – the force that binds protons inside the nuclei of atoms. Physicists have theorized since the 1960s, and ample experimental evidence since has confirmed, that hadrons are made up of quarks and antiquarks that determine their properties. A subset of hadrons, called mesons, is formed from quark-antiquark pairs, while the rest – baryons – are made up of three quarks. ... The Belle Collaboration reported the first evidence for the Z(4430) in 2008. They found a tantalizing peak in the mass distribution of particles that result from the decays of B mesons. Belle later confirmed the existence of the Z(4430) with a significance of 5.2 sigma on the scale that particle physicists use to describe the certainty of a result. LHCb reports a more detailed measurement of the Z(4430) that confirms that it is unambiguously a particle, and a long-sought exotic hadron at that. They analyzed more than 25,000 decays of B mesons selected from data from 180 trillion (180x10^12) proton-proton collisions in the Large Hadron Collider."
Re: (Score:3, Funny)
She said it wasn't all that large.
I read it as Erotic Hadrons. (Score:3)
I'm not sure which is funnier.
Re: (Score:1)
Actually, I misread it as "erotic hardons" .
Re: (Score:1)
Hmmm, masse accounts of literary Freudian Slip
Much ado about the thought of erections....
Verrrrry interesting.........
Re: (Score:2)
Yeah, me too... and uhm... when did that change for you? I'm in mid-40s and that still happens for me though I wouldn't say without thinking... there's almost always something I'm thinking about at the time.
Re: (Score:2)
I first assumed that it was Ingress backstory.
From the beginning... (Score:4, Insightful)
Re: (Score:3)
Golf clap.
Re: (Score:2)
I swear I had to read that three times before I realized that the article title wasn't "LHCb Confirms Existence of Exotic Hardons"
"erotic hardons"
strange (Score:2, Interesting)
Re:strange (Score:5, Informative)
it is believe to be made of quarks, but instead of the usual two or three it has four, c c_ d u_
that means it has charge of negative one
Re:strange (Score:5, Informative)
It *is* made up of quarks - a charm quark, an anti-charm quark, down quark, and anti-up quark. The interesting thing is that this is a pairing never before seen - all previous hadrons were either two quarks (quark + antiquark of same color) or three quarks (three quarks or antiquarks, all of different colors). Two quarks and two antiquarks has been postulated but never observed, until now.
Re:strange (Score:4, Informative)
For a more useful perspective and pretty graph of the experimental data, see:
http://www.quantumdiaries.org/2014/04/09/major-harvest-of-four-leaf-clover
Re: (Score:2)
It is made of quarks, it's "just" that it doesn't seem to be a meson (quark +antiquark) or a baryon (3 quarks)
They're speculating that it's charm + anticharm + up + antidown, i.e 4 quarks (or 2 quark/antiquark pairs).
Probably bollocks.
Re:strange (Score:5, Informative)
To get Psi' you need c-cbar; to get a pi you need an up and a down. The final state they observe is a mu-,mu+ K pi. The production of the muons in pairs means that they came out of the same reaction -- that is you can put them together to get a Psi' with good reliability. So you that leaves you with Psi' k and pi, you could have an initial state that decays to a psi' and a (k+pi) in a baggy (aka the K* resonances), or a psi' and a k and a pi that don't interact with each other (but three prong decays are well down from pair wise decay chains), or a k + (psi' pi) in a baggy. Since momentum and energy are conserved having K*'s in the produced stuff can reflect into the other pairings (this is the crux of the venerable Dalitz plot analysis). The reflections are insufficient to explain away a k +(psi' pi) decay chain --it's not an echo from other known physics. The psi' is a pure ccbar state and the quark content of the pion is well known -- either all four quarks are present in the (psi' pi) baggy or something really weird is going on. Whip out the Occam's razor and you claim a tetraquark. (It's not clear however that the ancient a0(980) and f0(980) are not tetraquarks or molecules ... it's just a very very hard place to work -- here the muon decays help a lot at cleaning up the states -- there's not a great analog of the psi' below 1GeV that is a clean resonance to beat against.
Re: (Score:1)
Thanks, that sounds much less like bollocks than I thought.
Re: (Score:2)
No, it defines hadrons as follows: "Hadrons are subatomic particles that can take part in the strong interaction – the force that binds protons inside the nuclei of atoms." It then goes on to say that Hadrons are theorized to be constituted by quarks. Presumably the evidence they have for these particles being hadrons is that they take part in the strong interaction.
Re: (Score:2)
It's not made up of Quark's, it's made up of Rom's.
So what is it made of? (Score:2)
It's not a quark-antiquark pair. It's not three quarks of different colors. So what is it? Four quarks? Something else?
Re:So what is it made of? (Score:5, Informative)
According to http://lhcb-public.web.cern.ch... [web.cern.ch]
"It is therefore a four quark state or a two-quark plus two-antiquark state."
Re: (Score:2)
they call those "tetraquarks" in particle physics,
http://en.wikipedia.org/wiki/T... [wikipedia.org]
Re: (Score:3, Informative)
"Tetraquarks" are a two-quark plus two-antiquark state.
The other possibility that was mentioned (a four quark state) is too exotic to be reasonable (it would break color neutrality).
Re: (Score:1)
Funny, this is the one slashdot story I've seen where the AC's make more sense than the registered users.
Re: (Score:2)
Four quarks! (Score:4, Informative)
Re: (Score:3, Informative)
MUSTER Mark.
Re: (Score:2)
So it's still regular matter. It's just a little quarkier than most matter.
Re: (Score:2)
Re: (Score:2)
Exactly what I was just about to ask.
hadrons are made up of quarks and antiquarks that determine their properties. A subset of hadrons, called mesons, is formed from quark-antiquark pairs, while the rest – baryons – are made up of three quarks.
And the exotic hadrons...?
This "summary" appears to be simply paragraphs 1, 2, 4 and 5 from the article, with the submitter's sole contribution being to delete paragraph 3, which gives us the pertinent information that:
But since it was first proposed physicists have found several particles that do not fit into this model of hadron structure. Now the LHCb collaboration has published an unambiguous observation of an exotic particle – the Z(4430) – that does not fit the quark model.
So, that explains that.
http://en.wikipedia.org/wiki/E... [wikipedia.org]
Re:So what is it made of? (Score:5, Funny)
Fuck it, we're doing five quarks.
Would someone tell me how this happened? We were the fucking vanguard of particles in this universe. The meson was the hadron to own. Then the other guy came out with a three-quark nucleon. Were we scared? Hell, no. Because we hit back with a little thing called the proton. That's three quarks and a positive charge. For positivity. But you know what happened next? Shut up, I'm telling you what happened—the bastards went to four quarks. Now we're standing around with our cocks in our hands, selling three quarks and a charge. Charge or no, suddenly we're the chumps. Well, fuck it. We're going to five quarks.
Re: (Score:3)
Sure, we could go to four quarks next, like the next universe over. That seems like the logical thing to do. After all, three worked out pretty well, and four is the next number after three. So let's play it safe. Let's make a thicker gluon field and call it the Quark3SuperTurbo. Why innovate when we can follow? Oh, I know why: Because we're a fundamental force of the universe, that's why!
Now we're standing around with our cocks in our hands
Such a missed opportunity for the word "hadron".
Re: (Score:1)
Re: (Score:2)
Re: (Score:2)
Onion? This isn't Onion.
This. Is. SLASHDOT!
Re: (Score:2)
You never go full hadron.
4 quarks particle (Score:3, Informative)
From the original publication ( http://lhcb-public.web.cern.ch/lhcb-public/ ):
The minimal quark content of the Z(4430) state is: charm + anti-charm + down + anti-up.
It is therefore a four quark state or a two-quark plus two-antiquark state.
Implications for the Standard Model (Score:4, Interesting)
Re:Implications for the Standard Model (Score:5, Informative)
Re: (Score:2)
It means we're one step closer to confirming theoretical constructs such as wormholes as we're rapidly approaching the stage where exotic matter is no longer theoretical, and things such as negative mass start to look achievable.
Not that this observation makes all of that actually true, but we're still moving in the right direction to maybe eventually one day confirm and observe things such as stable wormholes.
Re: (Score:1)
So is this evidence for or against Lisi's theory? (Score:2)
Lisi's "An Exceptionally Simple Theory of Everything" predicts particles. Is this one of those particles that it predicts?
http://en.wikipedia.org/wiki/A... [wikipedia.org]
Re: (Score:3)
Lisi's theory predicts fields and the kind of particles known as bosons, it's a field theory that hasn't even been refined enough to include quantization. It doesn't predict mass of particles either.
Is Slashdot all 12 year old boys now? (Score:3, Insightful)
18 comments in, and 17 of them are just stupid stuff about hard-ons. Either Slashdot has been taken over by 12 year old boys, or they're all just still boys trapped in the bodies of men.
Re: (Score:1)
(Spock) His analysis is logical.
(Kirk): Yes, it is Spock. This is why we must talk about hard-ons instead.
(McCoy): You won't get me to talk about his green-blood filled hard-on. Damn it Jim, I'm a doctor, not a schoolboy!
Re: (Score:1)
Nope.. we all moved to http://soylentnews.org/ [soylentnews.org]
Re:Is Slashdot all 12 year old boys now? (Score:5, Insightful)
Re: (Score:2)
Not to mention first posts!, Beowulf clusters, can I play Quake/Crysis on that, etc.
Re: (Score:3)
Re: (Score:2)
Don't kid yourself. "Men" in the form you romanticize do not exist. All men are "boys" at heart, and remain so irrespective of age.
There's a reason why male-oriented comedy is filled with penis jokes. They're not just targeting the teenage demographic.
Re: (Score:1)
For slightly less purile fun, look at https://www.youtube.com/watch?... [youtube.com] (The large haddock collider)
Editorial/stats geekiness (Score:5, Insightful)
Belle later confirmed the existence of the Z(4430) with a significance of 5.2 sigma on the scale that particle physicists use to describe the certainty of a result.
I believe that "scale" is called the normal distribution; that is to say, the odds of getting that result as a fluke are the same as finding a point 5.2 standard deviations away from the mean of the normal curve. If so, everything in that sentence after "5.2 sigma" can be left out.
Re: (Score:2)
As the sigmas go up, the so does the probability that your experiment was flawed.
Economics isn't the dismal science, statistical inference is.
Re: (Score:2)
Well, to a lay person it might sound a little like "Belle later confirmed the existence of the Z(4430) with [something]", common folk don't talk about probability in terms of "a significance of 5.2 sigma".
A better phrasing would be:
Belle later confirmed the existence of the Z(4430) with a significance of 5.2 sigma, a certainty high enough to be considered a discovery in particle physics.
Changes in current knowledge (Score:2)
Since I could no longer comprehend the technical nature of the discovery, what is the consequence of this discovery? Will existing theories be changed (or validated)? Any complications to other theories?
I hope someone with more knowledge in the subject matter will be able to share.
Re: (Score:2)
what is the consequence of this discovery?
Some idle speculation has finally been confirmed.
Will existing theories be changed (or validated)?
Not really. There was no particular reason to think this was impossible. We just didn't have any evidence it was possible.
Any complications to other theories?
Not to any useful theories. Theories like the Electric Universe have one more thing added to the list of things they can't explain, but that's no surprise. :)
LHCb Confirms Existence of Exotic Hadrons (Score:1)