The Relativistic Heavy Ion Collider Makes Some Noise

November 21, 2008 By Laura Mgrdichian feature
An aerial view of the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory in Upton, NY. Image: AIP

(PhysOrg.com) -- A group of physicists studying heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC), a large particle accelerator located on Long Island, New York, recently showed that the collisions can create acoustic shock waves -- sonic booms. This new information could be used to learn even more about the intriguing state of matter produced during the collisions.

The matter, known as a quark-gluon plasma, is produced because the collisions are so energetic and hot that the ions' constituent particles, quarks and gluons -- known collectively as partons -- which are normally tightly bound together, "melt" into a fluid-like particle soup.

"What does a quark gluon plasma sound like? We wanted to find out," said Duke University physicist Bryon Neufeld to PhysOrg.com, the paper's corresponding author. "Sound waves are commonly used as a probe of everyday matter. But sound may also be a useful tool for researching matter at temperatures many thousands of times hotter than the sun.

"Our work addresses the question of sound from a different perspective: What is the sound generated by highly energetic particles moving through the quark-gluon plasma, and how can we use it to explore the properties of the plasma?"

Neufeld co-authored the paper on this research, appearing in the October 13 edition of Physical Review C, with physicists Berndt Mueller (Duke University) and Jorg Ruppert (McGill University, Montreal, Canada and J. W. Goethe-Universitat, Frankfurt, Germany).

The group was looking for evidence of a Mach cone -- the cone-shaped shock wave caused by the pressure difference created when an object, like an airplane or particle, exceeds the speed of sound in that particular medium (the speed of sound is different in different media).

Said Neufeld, "Highly energetic particles traveling faster than the speed of sound may produce characteristic sound patterns, such as Mach cones, which create distinctive experimental signatures. These experimental signatures can help determine certain characteristics of the medium they are traveling through, such as the speed of sound and viscosity."

After the heavy-ion beams collide (in this case the beams consisted of either gold or lead nuclei), some partons back-scatter into the plasma rather than out of it. The physicists modeled the case of a single parton moving through the plasma, depositing energy and momentum in its wake. They took that model and used it to solve the hydrodynamic equations of the plasma. The solutions show that, mathematically, if the parton is moving faster than the speed of sound in the plasma a Mach cone trails behind it.

Citation: Phys. Rev. C 78, 041901 (2008)

Copyright 2008 PhysOrg.com.
All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.

Explore further: New X-ray actions revealed

Related Stories

New X-ray actions revealed

July 23, 2015

Potentially destructive high-energy electrons streak into Earth's atmosphere from space, not as Shakespeare's "gentle rain from heaven," but at velocities approaching the speed of light.

Sunny, with a chance of nuclear bullets

July 23, 2015

In space, far above Earth's turbulent atmosphere, you might think the one thing you don't have to worry about is weather. But you would be wrong. Just ask the people charged with the safety of the Cloud-Aerosol Lidar and ...

Six things you didn't know about MESSENGER's Mercury crash

April 29, 2015

The MESSENGER spacecraft left Earth in 2004 carrying among its instruments a sensor built at Michigan Engineering's Space Physics Research Lab. Over the years, some 75 U-M researchers, including faculty members, engineers ...

Recommended for you

Quantum matter stuck in unrest

July 31, 2015

Using ultracold atoms trapped in light crystals, scientists from the MPQ, LMU, and the Weizmann Institute observe a novel state of matter that never thermalizes.

New blow for 'supersymmetry' physics theory

July 27, 2015

In a new blow for the futuristic "supersymmetry" theory of the universe's basic anatomy, experts reported fresh evidence Monday of subatomic activity consistent with the mainstream Standard Model of particle physics.

Rogue wave theory to save ships

July 29, 2015

Physicists have found an explanation for rogue waves in the ocean and hope their theory will lead to devices to warn ships and save lives.

Researchers build bacteria's photosynthetic engine

July 29, 2015

Nearly all life on Earth depends on photosynthesis, the conversion of light energy into chemical energy. Oxygen-producing plants and cyanobacteria perfected this process 2.7 billion years ago. But the first photosynthetic ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

dvoss
3 / 5 (2) Nov 21, 2008
In regards your story
http://www.physor...980.html
readers may also be interested in the
commentary that accompanied the article in
Physical Review C at
http://physics.ap...es/v1/29
Readers who come in via this commentary can
access the PRC article for free.
Absolute
not rated yet Apr 28, 2009
Real Quark-Gluon Plasma Model 100% clearer than RHIC output
Recently, we have discovered a new process that can propose better outputs of Quark-Gluon Plasma than those of the RHIC. Mr.Tepparat Songkraw, a creator of this model, entitles his process as %u201CRelativistic Electron Repetition%u201D or %u201CRER%u201D. Its outputs are called Absolute Quark-Gluon Plasma model which is a part of Absolute Plasmon model.
Its images can be illustrated as follows:
http://www.absolutebase.com

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.