US particle collider produces post-Big Bang matter droplets

Experiments being conducted at the US Department of Energy Brookhaven National Laboratory in Upton, New York have produced tiny droplets of primordial state of matter that existed in the moments immediately following the Big Bang, according to published reports.

The matter is known as a quark-gluon plasma (QGP), Discovery News said, and is predicted to exist in temperatures and densities too extreme for regular matter. Instead, a “perfect liquid” can exist for a very brief period of time before cooling and condensing into ordinary matter.

Physicists using the Brookhaven Lab’s Relativistic Heavy Ion Collider (RHIC) recreated QGP and demonstrated that it flows like a nearly friction-free liquid. Furthermore, their work confirmed that collisions of smaller particles can also create droplets of this so-called primordial soup when they collide with larger nuclei (only on a much smaller scale).

“These tiny droplets of quark-gluon plasma were at first an intriguing surprise,” Berndt Mueller, associate director for nuclear and particle physics at Brookhaven, said in a statement. “Physicists initially thought that only the nuclei of large atoms such as gold would have enough matter and energy to free the quark and gluon building blocks that make up protons and neutrons.”

However, Mueller added, “the flow patterns detected by RHIC’s PHENIX (Pioneering High Energy Nuclear Interaction eXperiment) collaboration in collisions of helium-3 nuclei with gold ions now confirm that these smaller particles are creating tiny samples of perfect liquid QGP.”

New results build on previous findings from LHC

Researchers working at RHIC, as well as physicists at the CERN Large Hadron Collider (LHC) in Switzerland, have been working to recreate the formation of this primordial state of matter for a long time, Discovery News said. Two years ago, LHC physicists also announced the discovery of these quark-gluon plasma droplets after slamming protons into lead ions.

However, the website added, the Brookhaven experiments mark the first time that helium-3, a light ion, has been collided with heavy ions (gold) to produce QGP signatures. This indicated that the substance could be produced at lower energies, giving physicists the opportunity to study this primordial plasma, which has not existed naturally in nearly 14 billion years.

“The idea that collisions of small particles with larger nuclei might create minute droplets of primordial quark-gluon plasma has guided a series of experiments to test this idea and alternative explanations, and stimulated a rich debate about the implications of these findings,” said Jamie Nagle, a physicist at the University of Colorado and co-spokesperson for the PHENIX team.

“These experiments are revealing the key elements required for creating quark-gluon plasma and could also offer insight into the initial state characteristics of the colliding particles,” he added. A paper detailing the team’s findings will be published in the journal Physical Review Letters.

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Pictured is the PHENIX detector used to find this special state of matter. Credit: Brookhaven Lab RHIC.