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New 'Mystery Meson' Sub-Atomic Particle Discovered
securitas writes "The BBC reports that scientists in Japan have discovered a new sub-atomic particle that defies current theories of matter and energy. The 'mystery meson' X(3872) was revealed while studying beauty quarks at the KEK High Energy Accelerator Research Organization Tsukuba meson factory. 'It weighs about the same as a single atom of helium and exists for only about one billionth of a trillionth of a second before it decays into other longer-lived, more familiar particles.' Scientists say the lifespan 'is nearly an eternity for a sub-atomic particle this heavy' and may require a change in current theory. Possible explanations for this include the particle being comprised of two quarks and two antiquarks, instead of the usual one-one pairing. More explanation and illustrations at KEK."
from the Institute of Physics
When anger rises, think of the consequences.
Confucius (551 BC - 479 BC)
No, they think it is most likely to be a combination of four quarks - charm/anti-charm and up/anti-up. This hasn't been seen before but is perfectly valid under the standard model... they've already seen pentaquark states after all.
Jon Erikson, IT guru
Too bad the US cancelled the Superconducting Supercollider some years back.
Why? It cost too much.
And how much are we spending in Iraq for benefits denied to our own citizens?
Priorities?
gotta love how they study something by smashing it into peices. I always pictured using the same technique to study how a radio works by shooting bullets into it, and then observing the peices as they fly out of the radio :-)
I Am My Own Worst Enemy
According to the articals the particle doesn't violate the Standard Model, however, the current Standard Model will need a change to allow for this particle. Of course it should be noted that the Standard Model is a patch-work affair based on observation with out much understanding of how everything fits together and as such will still don't know how everything works.
Save Sam and Max!
How do we know that you didn't have a purple dragon in your garage for about one billionth of a trillionth of a second?
I'm not surprised that unsual particles like this are being discovered. Perhaps the long halflife of this particle suggests that aggregation can lead to stablization. In the same way that neutrons are stabilized by protons on the nuclei of everyday matter, I'd bet that mesons can be stabilized either by other mesons or baryons.
Perhaps this won't overturn pre-existing models for elementary particles, but lead to extensions of theories on how aggregates of these particles behave.
Two wrongs don't make a right, but three lefts do.
...ever get the feeling that partical physicists are just sharing one big self-delusion?
"Hey Bob, did you hear? Joe discovered a new kind of...uh...Meson!"
"A...Meson? Oh...yeah, Meson, of course. I know what that is."
"Yeah, check out this graph, see that spike right there for 1 billionth-trillionth of a second?"
"Uh...yeah! Yeah, I see it! Right there!"
"No, over there."
"Right! Right over there! Wow, that's great. Well, I'm off to go discover a...uh...new kind of...Foofara?"
"Wow....Foofara huh? Wow...that's awesome...Good Luck!"
"Another Contradiction" is much too strong a statement. The Standard Model has two problems (1) it doesn't play well with gravity, so it can't be the "final answer", and (2) it is so ridiculously successful that no one knows quite where to go next in theoretical particle physics. The SM is more or less able to give the right answer to any question we're able to ask it, right up to the edges of black holes or the first tiny fraction of a second after the birth of the universe. There are some problems too complex for our calculational techniques and approximations (i.e. we can't calculate the physics of many bound states precisely or derive human behavior), but there aren't really any contradictions. The recently reported new particle is more likely to lead us to tell us our calculational approximations aren't very good, rather than that something fundamentally new (though one can always hope!) Particle physicists are always hoping to find something fundamentally wrong with the standard model - it's just an extremely good approximation to the right answer, and until the approximation breaks down you don't know how to improve it.
The whole point of the scientific method is that you get a model that works; then, somewhere down the road, you find something new and your model doesn't work anymore, so you change the model.
Our thinking about how subatomic particles work - even to the most basic level that we have "particles" (well, wave packets, but..) that we envision as skittering around interacting and such - is only valid because it works.
The question "Well, then, what is actually going on?" is meaningless. You don't actually know, and so you make better and better models to find out. In the end, you may have a model based on thinking of atoms as little cats; that may not be "what's actually going on", but if it fits experiment then what's the real difference?
A college Philosophy professor of mine tells a story about high energy physics and the practitioners thereof. He was researching a book on the philosophy of science and was interviewing one of the researchers at Fermilab (I think).
After discussing some of the esoterica of the field, my professor says "Okay. Off the record, do you *actually* believe that some of these particles exist outside of mathematical equations?"
Scientist looks around and replies "Not really. But this stuff is a lot of fun!"
"As God is my witness, I thought turkeys could fly." A. Carlson
If you were suggesting a vast, global conspiracy of physicists has organized itself to fraudulently claim the existance of a particle which is of interest mostly only to them- then I think you need to adjust your tinfoil hat.
Probably not very much, but who knows? String theory generally deals with phenomena at energy scales MUCH higher than these accelerators are dealing with, so high in fact that it really doesn't make any useful predictions about ordinary phenomena (even particle accelerator phenomena!) It's sort of like trying to predict the shape of a snowflake if all you've ever seen is steam. That's one of the main complaints about the theory - it may be right, it may be wrong, but it doesn't have any major prospects for predictions we could even test!
Sure, quark-antiquark pairs are fine (mesons). Triplets are fine (baryons). And Pentaquarks are (anti :-)strange, but fine (u,u,d,d,!s).
My "WTF happened to QCD" was in regards to a comment implying that X(3872) was a four-quark static configuration, which I thought was unkosher.
Did someone find the Jaffe tetraquark or hexaquark and I've just been in a cave for the past decade? :) It's been a long time since I seriously studied any of this, and most of the papers I just googled were dated within the last 5 years, so I won't be at all embarassed to be proven dead wrong.
Just one more sensation out of misunderstood
//charge +1 //charge -1 //charge 0 //charge 0 //charge 0
//charge +1 //charge 0 //charge -1
scientific paper.
I work with the team which confirmed it at Fermi in X(3872) -> J/Psi Pion Pion.
Some background on quarks first:
There are six quarks d, u, s, c, b, t. The heaviest are on the right.
And six antiquarks d(bar), u(bar), s(bar)... you've got the idea.
d, s, b have charge -1/3.
u, c, t have charge 2/3,
antiquarks and quarks have opposite charge.
All the matter consist of the particles which
are combinations of quarks. There are several
types of observed combinations: Mesons, Barions,
Tetraquarks, Pentaquarks. They are correspondingly
consist from 2, 3, 4 or 5 quarks.
All the Mesons consist of quark and antiquark. Examples:
Pion = (u, d(bar));
Kaon =(s, u(bar));
J/Psi =(c, c(bar));
D =(c, u(bar));
D(bar)=(c(bar), u);
Barions consist of 3 quarks. Examples:
Proton =(u, u, d );
Neutron =(d, d, u );
Antiproton =(u(bar), u(bar), d(bar));
You may continue it yourself for Tetraquarks and Pentaquarks.
Make sure the total charge of the particle is integer.
Heavy quarks want to decay to a ligter ones.
Eventually to u, d, u(bar), d(bar) and also
leptons (electron, muon) neutrinos and photons.
Some people think that X(3872) is one of the exited states of (c, c(bar)). Some people think
that it could be a tetraquark (c, c(bar), u, u(bar)). We should observe other modes
to know for sure. I am looking for X(3872) -> DD (bar).
No luck so far.
It is definitely very exiting to see a new particle like it would be exiting
to see a new chemical element. As far as I know it fit quite nicely
in the standard model - the analog of the Mendeleev table for particle physics.