exotic hadrons

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Messages 1 - 20 of total 21 in this topic << First  |  < Previous  |  Show All  |  Next >  |  Last >>
Dave Kos

Social climber
Temecula
Topic Author's Original Post - Apr 9, 2014 - 10:39am PT
It's science!

http://home.web.cern.ch/about/updates/2014/04/lhcb-confirms-existence-exotic-hadrons

Were you expecting something else? ... then why did you click?
this just in

climber
north fork
Apr 9, 2014 - 10:53am PT
Ok, I'll bite. I thought this was gunna be about exotic hardons. What a let down, really deflated, and feeling limp now.
mechrist

Gym climber
South of Heaven
Apr 9, 2014 - 11:44am PT
I started another thread just for you just in
mouse from merced

Trad climber
The finger of fate, my friends, is fickle.
Apr 9, 2014 - 11:59am PT
Dave, it's scientific porn, pornographic science, and a Chinese Fire Drill combined.

I wouldn't spend 20p, let alone 20 quid.
http://iopscience.iop.org/1674-1137/34/9/089/pdf/1674-1137_34_9_089.pdf
jonnyrig

Trad climber
formerly known as hillrat
Apr 9, 2014 - 11:59am PT
Still cant explain gravity, magnetism, whether or not god exists, and our purpose in life.
Dingus Milktoast

Gym climber
Maestro, Ecosystem Ministry, Fatcrackistan
Apr 9, 2014 - 12:02pm PT
Neither can you johnnyrig. Get busy!

DMT
this just in

climber
north fork
Apr 9, 2014 - 12:19pm PT
Haha, thanks Dr Christ.
jonnyrig

Trad climber
formerly known as hillrat
Apr 9, 2014 - 12:24pm PT
damn. ya got me. hell, I have trouble remembering what I ate.

Gravity's an unforgiving bitch, magnetism comes in handy if you remember your compass, I'm probably what ya'd call agnostic, and I hope someday I'll make the world a better place.
Oh, and science is neat.

How's that?
Dingus Milktoast

Gym climber
Maestro, Ecosystem Ministry, Fatcrackistan
Apr 9, 2014 - 12:37pm PT
Perfect. Thanks bro. I like it.

DMT
moosedrool

climber
lost, far away from Poland
Apr 9, 2014 - 12:46pm PT
Mouse, I didn't know you like Chinesse. Stay away from hadrons, though, they are full of quacks ;)

Moose
Ed Hartouni

Trad climber
Livermore, CA
Apr 10, 2014 - 02:12am PT
Still cant explain gravity, magnetism, whether or not god exists, and our purpose in life.
probably a better statement would be:
Still hasnt explain gravity, magnetism, whether or not god exists, and our purpose in life.
which would be accurate, "can't" would be difficult to prove.

as for the exotic hadrons...
...the standard model and Quantum Chromodynamics is the current model of particle physics that is used to explain (and predict) these subatomic phenomena.

In the early 1960's Murray Gell-Mann and Yuval Ne'eman proposed that the mesons and the baryons all belonged to various groups of eight particles (with an associated single particle assigned to each group). They called it the "Eightfold Way," and predicted the existence of a yet-to-be-discovered particle, the hyperon Ω⁻.

http://en.wikipedia.org/wiki/Eightfold_Way_(physics);


Taking these groups seriously (as in mathematically seriously) the belong to a class of Lie algebras known as SU(3). These SU(3) groups can be built up out of fundamental representation
of a three element "vector." This fundamental representation was interpreted as a physical particle which we call "quarks"
http://en.wikipedia.org/wiki/Special_unitary_group

At the time there were only three needed to define the observed particle spectrum. We refer to those as the "up" "down" and "strange" quark and build all the particles up out of combinations of either three quarks or a pair of quark and anti-quark. This was first described by Gell-Mann and George Zweig.
http://en.wikipedia.org/wiki/Quarks
Gell-Mann got the name from Finnegans Wake
Three quarks for Muster Mark!
Sure he has not got much of a bark
And sure any he has it's all beside the mark.


the hyperon which was predicted was theorized to be composed of three strange quarks (sss) and it was discovered by Nick Samois' team at BNL in a bubble chamber:


Since that time three additional quarks have been found: charm, bottom and top.

Gell-Mann's SU(3) symmetry, and it's extensions, worked too well. For decades, the only hadrons we would find (the class of hadrons includes baryons like the proton and the neutron, and the Ω⁻ as well as mesons such as the pion, etc).

Worked too well because as the theory evolved into the Standard Model with QCD, we expected other combinations to be possible, including more than the three quarks or two quark and anti-quark combinations.

For instance, why not a particle with 2 quarks and 2 anti-quarks? or 4 quarks and an anti-quark? As far as the theory was concerned, these combinations were not forbidden. These are the so-called "exotic" hadrons.

There can also be excitations of the fields binding the quarks together, called "gluons" (because they "glue" the quarks into the hadrons). These gluon fields, when excited, would produce a spectrum of particles different from our normal spectrum. We haven't seen any evidence for such particles.

In fact, the theory might predict the existence of a hadron made up entirely of gluons along, called "glueballs" which exist because QCD is a nonlinear field theory (the gluons can interact with each other, unlike electromagnetism, where photons do not interact directly with each other.. at least in most regimes we've explored).

So the existence of these different types of particles has been anticipated for a long time, and now only recently being found.

I spent a lot of time looking for the lighter versions of these objects to no avail. It will be interesting to have some theoretical insight, but the theory is very difficult to calculate. So far only numerical calculations have been possible by "lattice QCD."

http://en.wikipedia.org/wiki/Lattice_QCD

lest you think this is all arcane, note that IBM's Blue Gene was built, originally, to execute lattice QCD calculations,
http://en.wikipedia.org/wiki/Blue_Gene
the Blue Gene architect, Al Gara, worked as a postdoc on one of my Fermilab experiments, and later went on to working at Columbia U. on QCD specific computer architectures.

These computers are among the fastest that exist.

The Z(4430) is thought to be composed of a charm, anti-charm, down and anti-up quarks, making it an exotic meson, a tetraquark object.

As far as other terms, we thought of coining the "hardon" when we were looking at an object that is called a Pomeron
http://en.wikipedia.org/wiki/Pomeron
whose QCD interpretation would be a multiple-gluon state. The Pomerons were thought to be "soft," consisting only of the gluons. Some experimental results from the ISR at CERN
http://en.wikipedia.org/wiki/Intersecting_Storage_Rings

had suggested that these Pomerons actually contained quarks too, a "hard" component. This object was Pomeron-like, but not the classical Pomeron, so we thought we might publish it as the "hardon"...

whimsy has its limits, however, especially since editors were wise to such things after John Ellis published about penguin-diagrams...

http://en.wikipedia.org/wiki/Penguin_diagram





Phil_B

Social climber
CHC, en zed
Apr 10, 2014 - 03:25am PT
Thanks for the physics history Ed. I do enjoy reading your posts.
Randisi

Social climber
Dalian, Liaoning
Apr 10, 2014 - 07:20am PT
Zweig wanted to call quarks aces, after the playing cards. He surmised there'd be four of them.

I used to be friends with his son.
Jim Clipper

climber
from: forests to tree farms
Apr 10, 2014 - 10:16am PT
All I got:

"Beauty Eh?!" Bob and Doug McKenzie

I remember gawking at cloud chambers. Thanks Mr. H, wonder if my understanding of science has progressed.
moosedrool

climber
lost, far away from Poland
Apr 10, 2014 - 10:32am PT
Ed, so you ALMOST got hardon.

Keep trying:-D

Nice summary, thanks!

Moose
Jan

Mountain climber
Colorado, Nepal & Okinawa
Apr 10, 2014 - 10:50am PT
Fun story about John Ellis and the Penguin diagram.

paul roehl

Boulder climber
california
Apr 10, 2014 - 12:27pm PT
Nice, but don't you find more insight in "three quarks for muster Mark."

"Murray Gell-Mann, the physicist who proposed this name for these particles, said in a private letter of June 27, 1978, to the editor of the Oxford English Dictionary that he had been influenced by Joyce's words: "The allusion to three quarks seemed perfect" (originally there were only three subatomic quarks). Gell-Mann, however, wanted to pronounce the word with (ô) not (ä), as Joyce seemed to indicate by rhyming words in the vicinity such as Mark. Gell-Mann got around that "by supposing that one ingredient of the line 'Three quarks for Muster Mark' was a cry of 'Three quarts for Mister . . . ' heard in H.C. Earwicker's pub," a plausible suggestion given the complex punning in Joyce's novel. It seems appropriate that this perplexing and humorous novel should have supplied the term for particles that come in six "flavors" and three "colors." "

Can the story of Tristan and Isolde tell us more about the nature of being than an inquiry into the Infinitesimal?

But Hadron? Not a very insightful or creative name... thick?
Ed Hartouni

Trad climber
Livermore, CA
Apr 10, 2014 - 01:25pm PT
leptons are, originally, "light" particles,

The name lepton comes from the Greek λεπτόν (leptón), neuter of λεπτός (leptós), "fine, small, thin"
http://en.wikipedia.org/wiki/Lepton


hadrons are heavy,
In particle physics, a hadron i/ˈhædrɒn/ (Greek: ἁδρός, hadrós, "stout, thick")
http://en.wikipedia.org/wiki/Hadrons

so if you like botany, these are classical language descriptors in the tradition of naming things after their morphological expressions...

you might not find it interesting, Paul, it is, I suppose a matter of taste...

but it does reflect the human spirit, in all these stories. I could understand that this sort of thing is a boring to many people.

I've a friend who is a cultured New Yorker who finds the sculptural design of Fermilab to be unsophisticated... but I rather like it, if for no other reason then the effort in coming up with something physically esthetic to balance the intellectual esthetics of what goes on there...














paul roehl

Boulder climber
california
Apr 10, 2014 - 02:58pm PT
No, really I find it absolutely fascinating. I just think it's interesting the term quark comes from what may be the pinnacle of Western literature in the 20th century. I see art and science as two peas from the same pod.
Ezra Ellis

Trad climber
North wet, and Da souf
Apr 11, 2014 - 08:30am PT
Thanks for the history lesson Ed!!!!!
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