Subscribe free to our newsletters via your
. 24/7 Space News .

Exotic Particle Confirmed
by Staff Writers
Julich, Germany (SPX) Jun 10, 2014

The Julich accelerator COSY (cooler synchrotron) with a circumference of around 180 metres provides high-precision beams of spin-polarized protons and deuterons for experiments. Image courtesy Forschungszentrum Julich. For a larger version of this image please go here.

or decades, physicists have searched in vain for exotic bound states comprising more than three quarks. Experiments performed at Julich's accelerator COSY have now shown that, in fact, such complex particles do exist in nature. This discovery by the WASA-at-COSY collaboration has been published in the journal Physical Review Letters.

The measurements confirm results from 2011, when the more than 120 scientists from eight countries discovered for the first time strong indications for the existence of an exotic dibaryon made up of six quarks.

For a long time, physicists were only able to reliably verify two different classes of hadrons: volatile mesons comprising one quark and one antiquark and baryons consisting of three quarks. Protons and neutrons, which make up atomic nuclei, are examples of the latter. In recent years, however, there has been growing evidence for the existence of additional types of hadrons, for example, hybrids, glueballs, and multiquarks.

In 1964, the physicist Freeman Dyson was the first to predict such more complex states. But any reliable verification proved impossible for many years because almost no measurements could be reproduced.

Only recently, other research groups - independently of each other - found strong indications for short-lived, exotic particles comprising four quarks, so called "tetraquarks".

The new bound state, which has now been verified at COSY, means that yet another class of exotic particles has been identified. "The new resonance that we observed confirms that quarks really do exist in six-packs. This discovery could open the door to new physical phenomena," says group spokesman Prof. Heinz Clement from the University of Tubingen.

The structure that was first discovered in 2011 is extremely short-lived and could only be detected via its decay products. The transient intermediate state - technical term: resonance - exists for a mere hundred-sextillionth (10 to the power of -23) of a second before it decays. This time span is so short that, for example, light can travel just a distance equivalent to the diameter of a small atomic nucleus.

Whether all six quarks form a single compact entity or rather a "hadronic molecule" has yet to be clarified. The latter would be composed of several nuclear building blocks - for example of excited protons and neutrons bound to each other - yet much more strongly than inside an atomic nucleus.

"The measurements that we performed at COSY in 2011 were already very precise. But because the experiments could not be repeated at any other accelerator worldwide, we had to come up with another experiment to verify the results," explains Prof. Hans Stroher, director at the Nuclear Physics Institute (IKP-2) in Julich.

In order to gain further unequivocal evidence of the exotic resonance named d*(2380), the scientists scanned the relevant energy range in an elastic scattering experiment.

They bombarded a proton target with polarized, heavy hydrogen nuclei known as deuterons. The exotic bound state formed during the collision influenced the angle with which the particles moved away from each other after the collision, thus allowing it to be identified .

"The findings are part of a bigger picture. If this particle exists, then theoretically a whole range of other exotic states can be expected," says director at Julich's IKP-1 Prof. James Ritman. The nuclear physicist is in charge of Julich's contribution to the PANDA detector at the international accelerator complex FAIR in Darmstadt, where such exotic structures will be explored in more detail.


Related Links
Forschungszentrum Julich
Understanding Time and Space

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Controlling Complex Systems Comprising Many Quantum Particles
Vienna, Austria (SPX) Jun 05, 2014
At TU Vienna, a new method was developed to utilize quantum mechanical vibrations for high precision measurements. The well-known concept of the Ramsey interferometer is applied to a complex multi particle system consisting of hundreds of atoms. Sometimes quantum particles behave like waves. This phenomenon is often used for high precision measurements, for instance in atomic clocks. Usual ... read more

55-year old dark side of the moon mystery solved

New evidence supporting moon formation via collision of 2 planets

NASA Missions Let Scientists See Moon's Dancing Tide From Orbit

Earth's gravitational pull stretches moon surface

Opportunity Recovering From Flash Memory Problems

Rover Corrects its Spacecraft Clock

NASA could not deliver humans to Mars

Big Brother creators to document Mars One mission

Astronaut Mike Hopkins says space smells

NASA Announces Two Upcoming Undersea Missions

Orion Crew And Service Modules Stacked

Towards manned orbital mission: Iran to build its own spacecraft

Chinese lunar rover alive but weak

China's Jade Rabbit moon rover 'alive but struggling'

Chinese space team survives on worm diet for 105 days

Moon rover Yutu comes closer to public

Russia, US resume talks on new joint projects for ISS

Russian Soyuz with New Crew Docks at ISS in Automatic Mode

Russian, German and US astronauts dock with ISS

Six-Person Station Crew Enjoys Day Off Following Docking

Lie detector exposes sabotage of Proton-M booster

Next ATV transferred to Final Assembly Building at Kourou

Roscosmos Scolded for 'Pestering Society' with Proton Crash Theories

SpaceX unveils capsule to ferry astronauts to space

Kepler space telescope ready to start new hunt for exoplanets

Astronomers Confounded By Massive Rocky World

Two planets orbit nearby ancient star

First light for SPHERE exoplanet imager

Raytheon selected to demonstrate next generation, modular radar system

Analyzing Resistance to Impacts and Improving Armor Plating

Boeing Completes 2nd 702HP Satellite for the Government of Mexico

Northrop Grumman to Supply Navigation System SKorea's KOMPSAT-2 Birds

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.