Printer Friendly

Hints emerge of a four-quark particle.

Physicists at accelerators in Japan and the United States have detected a subatomic particle that may be unlike any seen before.

Some evidence suggests that the particle contains two pairs of more fundamental particles--quarks and antiquarks--bound together. If that's verified, then the new find would be the first four-quark particle known.

Until recently, quarks and antiquarks were observed only in groups of twos or threes. However, twice this year, researchers have reported possible five-quark particles (SN: 10/18/03, p. 245).

The discovery of yet other combinations of quarks and antiquarks could illuminate the force that binds quarks and antiquarks together. Physicists call this the strong force.

Experimenters at the High Energy Accelerator Research Organization (KEK) laboratory in Tsukuba, Japan, noted the first signs of the new particle while examining the aftermaths of hundreds of millions of electron-positron collisions. When the KEK investigators stumbled upon the intriguing new particle, they were seeking a previously undiscovered but mundane quark-anti-quark duo--that remains unobserved.

A team at Fermi National Accelerator Laboratory (Fermilab) in Batavia, Ill., confirmed the KEK results, which are chronicled in an upcoming Physical Review Letters.

Some theorists suspect the new find may be deceptive. The calculations that guided the KEK team might have been inadequate for predicting the properties of the duo particle the team was seeking, proposes Fermilab theorist Estia J. Eichten. In that case, the newfound particle could actually be the duo, but with characteristics that only seem unexpected. On the other hand, Eichten notes, the large mass of the new particle closely matches that expected if two quark-antiquark D-mesons got hitched.
COPYRIGHT 2003 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2003, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:Physics
Publication:Science News
Article Type:Brief Article
Geographic Code:1USA
Date:Dec 13, 2003
Words:264
Previous Article:Warm-blooded plants? Ok, there's no blood, but they do make their own heat.
Next Article:Nanoparticles hunt down and kill tumors.
Topics:


Related Articles
Proton puzzle puts physicists in a whirl.
Beyond the Z: the latest generation of high-powered particle accelerators has produced no real surprises. What's next?
Putting limits on the top quark.
In search of the elusive top quark.
Particles of history.
The stuff of protons: gluing quarks to make protons, neutrons, and atomic nuclei.
Beyond the top: now that physicists have found the top quark, what's next?
Microcosmic bang: mashing atomic nuclei to create a quark soup.
Exotic needle found in particle haystack.
Jiggling the cosmic ooze; a new blueprint for all the universe's mass and energy may be just around the corner.

Terms of use | Privacy policy | Copyright © 2022 Farlex, Inc. | Feedback | For webmasters |