Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Physicists Puzzle Over Unexpected Findings in ’Little’ Big Bang

12.11.2002


Scientists have recreated a temperature not seen since the first microsecond of the birth of the universe and found that the event did not unfold quite the way they expected, according to a recent paper in Physical Review Letters. The interaction of energy, matter, and the strong nuclear force in the ultra-hot experiments conducted at the Relativistic Heavy Ion Collider (RHIC) was thought to be well understood, but a lengthy investigation has revealed that physicists are missing something in their model of how the universe works.



"It’s the things you weren’t expecting that are really trying to tell you something in science," says Steven Manly, associate professor of physics and astronomy at the University of Rochester and co-author of the paper. "The basic nature of the interactions within the hot, dense medium, or at least the manifestation of it, changes depending on the angle at which it’s viewed. We don’t know why. We’ve been handed some new pieces to the puzzle and we’re just trying to figure out how this new picture fits together."

At RHIC in Brookhaven, NY., Manly and his collaborators on the PHOBOS experiment wanted to probe the nature of the strong nuclear force that helps bind atoms together. They smashed two atoms of gold together at velocities near the speed of light in an attempt to create what’s called a "quark-gluon plasma," a very brief state where the temperature is tens of thousands of times higher than the cores of the hottest stars. Particles in this hot-soup plasma stream out, but not without bumping into other particles in the soup. It’s a bit like trying to race out of a crowded room-the more people in your way, the more difficult to escape. The strength of the interactions between particles in the soup is determined by the strong force, so carefully watching particles stream out could reveal much about how the strong force operates at such high temperatures.


To simplify their observations, the researchers collided the circular gold atoms slightly off-center so that the area of impact would not be round, but shaped rather like a football-pointed at each end. This would force any streaming particles that headed out one of the tips of the football to pass through more of the hot soup than a particle exiting the side would. Differences in the number of particles escaping out the tip versus the side of the hot matter could reveal something of the nature of that hot matter, and maybe something about the strong force itself.

But a surprise was in store. Right where the gold atoms had collided, particles did indeed take longer to stream out the tips of the football than the sides, but farther from the exact point of collision, that difference evaporated. That defied a treasured theory called boost invariance.

"When we first presented this at a conference in Stony Brook, the audience couldn’t believe it," says Manly. "They said, ’This can’t be. You’re violating boost invariance.’ But we’ve gone over our results for more than a year, and it checks out."

Aside from revealing that scientists are missing a piece of the physics puzzle, the findings mean that understanding these collisions fully will be much more difficult than expected. No longer can physicists measure only the sweet spot where the atoms initially collided-they now must measure the entire length of the plasma, effectively making what was a two-dimensional problem into a three-dimensional one. As Manly says, this "dramatically increases the computing complexity" of any model researchers try to devise.

Modeling and understanding such collisions are extremely important because the way that the plasma cools-condensing like steam turning into water against a shower door-might shed some light on the mechanism that gives matter its very mass. Where mass itself comes from has been one of physicists chief conundrums for decades. Manly hopes that if we can understand exactly why the quark-gluon plasma behaves as it does, we might gain an insight into some of the rudiments of the world we live in.

"Understanding all the dynamics of the collision is really critical for actually trying to get the information we want," says Manly. "It may be that we have an actual clue here that something fundamental is different-something we just don’t understand." Smiling, he adds, "Yet.

Jonathan Sherwood | EurekAlert!
Further information:
http://www.rochester.edu/
http://www.rochester.edu/pr/News/NewsReleases/scitech/manly-quark.html

More articles from Physics and Astronomy:

nachricht First Juno science results supported by University of Leicester's Jupiter 'forecast'
26.05.2017 | University of Leicester

nachricht Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>