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New particle turns up in Japan
Physicsweb ^ | Nov 14, 2003 | Belle Dumé

Posted on 11/15/2003 8:43:52 PM PST by Diddley

The Belle collaboration at the KEK laboratory in Japan has discovered a new sub-atomic particle which it is calling the "X(3872)". The particle does not fit into any known particle scheme and theorists are speculating that it might be a hitherto unseen type of meson that contains four quarks (arxiv.org/abs/hep-ex/0309032; Phys. Rev. Lett. to be published).

The discovery has been confirmed by the CDF collaboration at Fermilab in the US, where the new particle is being called the "mystery meson". Mesons are particles that contain a quark and an antiquark that are held together by the strong nuclear force.

Since there are six different "flavours" of quark - up, down, strange, charm, bottom and top - it is possible to form a large number of different mesons.

The Belle team measured the decay of B-mesons - mesons that contain a bottom quark - produced in electron-positron collisions at the KEK B-factory in Japan. The team plotted the number of candidate events for B mesons against mass and observed a significant spike in the distribution at 0.775 GeV. This corresponds to a mass of nearly 3872 MeV. The particle decayed almost immediately into other, longer lived particles.

The KEK team says that the mass of this new meson is higher than theoretical predictions. Moreover, the way in which it decays also differs from theory. One possibility is that current models of the strong force need to be modified. Alternatively it could be that X(3872) is the first example of a "molecular state" meson that contains two quarks and two antiquarks.

Until recently particle physicists had only ever detected particles that contain two or three quarks. However, in the past year evidence has emerged for another four-quark particle known as the Ds(2317) and a five-quark particle known as the pentaquark.

Author Belle Dumé is Science Writer at PhysicsWeb


TOPICS: Japan; Technical
KEYWORDS: crevolist; japanparticle; meson; neutrino; neutrinodetector; neutrinos; newpalticurr; physics; quantumparticle; quark; science; stringtheory; subatomicparticle
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1 posted on 11/15/2003 8:43:53 PM PST by Diddley
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To: Diddley; Physicist; PatrickHenry; longshadow; RadioAstronomer
New particle turns up in Japan

Ah, well - that's my fault. I must have left it in my hotel room the last time I went to Japan on business. Sorry about that.

2 posted on 11/15/2003 8:46:34 PM PST by general_re (Me and my vortex, we got a real good thing....)
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To: Diddley
I think I understood 4 of those sentences!
3 posted on 11/15/2003 8:47:24 PM PST by BostonianRightist ("Society is produced by our wants, and government by our wickedness" -Thomas Paine)
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To: Diddley; PatrickHenry; Physicist; Piltdown_Woman; RadioAstronomer
Diddley: Thanks.

PH: Ping the science crew.

4 posted on 11/15/2003 8:48:23 PM PST by Virginia-American
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To: general_re
[2]
I'd put in for a claim if I were you. :-)
5 posted on 11/15/2003 8:49:20 PM PST by Diddley
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To: Diddley
Bump to the Mensa crowd....
6 posted on 11/15/2003 8:49:29 PM PST by demkicker
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To: general_re
It's 'cause you don't eat right.
7 posted on 11/15/2003 8:50:05 PM PST by Paul Atreides (Is it really so difficult to post the entire article?)
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To: Diddley
Eating subatomic particles in sushi may be harmful to your health says CDC.


8 posted on 11/15/2003 8:50:52 PM PST by jwalburg (You're not moderate just because you know leftier leftists than yourself)
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To: general_re
general_re said: "I must have left it in my hotel room the last time I went to Japan on business."

You must be running about a quark low, then.

9 posted on 11/15/2003 8:51:10 PM PST by William Tell
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To: William Tell
Who stranded me in Japan?


10 posted on 11/15/2003 8:52:34 PM PST by Paul Atreides (Is it really so difficult to post the entire article?)
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To: Diddley
They should name it the "Fugu"
11 posted on 11/15/2003 8:52:46 PM PST by WackyKat
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To: Diddley
Yatta?
12 posted on 11/15/2003 8:53:34 PM PST by P.O.E.
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To: All
I find the wit of FReepers to be hilarious. :-)
13 posted on 11/15/2003 8:54:33 PM PST by Diddley
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To: BostonianRightist
HUH??????? What did she say and what thehell is it?
14 posted on 11/15/2003 8:56:54 PM PST by BMC1
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To: Diddley
I think the cleaning lady must have swiped it. I tried calling about it, but the manager said that nobody had returned it to the desk. Now somebody's found my particle, and claimed it for themselves - I'm calling my lawyer first thing on Monday, that's for sure...
15 posted on 11/15/2003 8:58:05 PM PST by general_re (Me and my vortex, we got a real good thing....)
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To: Paul Atreides
It's 'cause you don't eat right.

I think it was the wasabi. Or maybe the sake. I always misplace stuff after having one too many of those...

16 posted on 11/15/2003 8:59:45 PM PST by general_re (Me and my vortex, we got a real good thing....)
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To: general_re
general_re said: "I think the cleaning lady must have swiped it."

If you're feeling energetic, you might check to see if there were any anti-quarks in the area at the time it disappeared.

17 posted on 11/15/2003 9:15:38 PM PST by William Tell
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To: Diddley
In the hunting of this quark, did they hunt it with railway shares and hot buttered toast?
18 posted on 11/15/2003 9:15:59 PM PST by AmericanVictory (Should we be more like them, or they like us?)
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To: AmericanVictory
They looked up, they looked down. They looked at the bottom and the top, but strangely, they were charmed (and they created a mess on it).
19 posted on 11/15/2003 9:21:33 PM PST by Diddley
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To: Diddley
LOST: Particle from Ennis Texas. May wander long distances. Has protons and neutrons. Reward if found and returned safely
20 posted on 11/15/2003 9:28:23 PM PST by GeronL (Visit www.geocities.com/geronl.....and.....www.returnoftheprimitive.com)
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