The announcement of the Bookhaven National Laboratory in the United States is detailed prescribe it The significance of the discovery, and we can be proud that another compatriot also made a significant contribution to the results. As Peter Petrichki, head of the laboratory’s Theoretical Nuclear Physics group, told our photo:
Now a 20-year search is over. We were able to verify the idea, which examined the behavior of materials created during the Big Bang, with calculations. Decades of methodological developments and the fastest computers in the world have helped us a lot in this matter.
As we can read in the article published in the journal Physical Review Letters, the transfer of momentum from the “liberated” quarks and gluons to the heavier quarks occurs to the maximum extent allowed by quantum mechanics.
The freed quarks and gluons interact so forcefully with the heavier quarks that they drag the rock-like particles with them.
Perfect liquid
Petreczky worked on the project for 19 years, he adds
The study of the materials of the early universe was the basis of the research. It was then 100,000 times hotter than the core of the sun. These extreme conditions were examined at the US Relative Heavy Ion Collider (RHIC) and the European Large Hadron Collider (LHC) at CERN. The most powerful supercomputers in the world have also helped us a lot.
The work was led by Petreczky and colleague Swagato Mukherjee and involved researchers from the Universities of Bielefeld, Regensburg, and Darmstadt in Germany, as well as the University of Stavanger in Norway.
The new analysis suggests that this material, known as a “quark-gluon plasma” (QGP), is a near-perfect fluid with a viscosity so low that it exceeds the limit set by quantum mechanics. Petreczky shows that as gold ions collide at RHIC, the boundaries of individual protons and neutrons dissolve, and elementary particles are released into protons and neutrons.
The matter created during the collision (quark-gluon plasma) has a low viscosity, so it flows almost frictionlessly. Its low viscosity also means that it sits between “melt” quarks and gluons highway extremely small. This free path means the distance a particle can travel before interacting with another particle.
In conventional matter, the free path length of a particle is very large, up to a thousand times the atomic size, but at the beginning of the universe the free path length of matter was very different, and we have now calculated it. This ancient substance flowed better than any of the traditional liquids we know today.
For the mean short free path, quarks and gluons are often closely relatedimpact. Collisions dissipate the energy of fast-moving particles, and the strongly interacting quark-gluon plasmas exhibit collective behaviour–including nearly frictionless flow.
simulation of ancient matter
“During the collision of two atomic nuclei, a thermal regime is obtained in one quadrillionth of a second” Petreczky said.
Because the interaction between particles in primordial matter was much greater, some particles did indeed show group behavior; On the one hand, this is not typical for conventional liquids, such as water, for such a small amount of molecules – for example, not a thousand water molecules flow out.
During the calculations, quark-gluon plasmas were simulated at certain temperatures and the heavy quark diffusion coefficient was calculated for several different temperatures.
Thus, the temperature dependence of the heavy quark interaction strength (and the mean free path of these interactions) was assigned. The heavy quark diffusion coefficient was immediately largest at the temperature at which the quark-gluon plasma forms.
The main result of the group’s calculations he led was the theoretical support of the empirical data.
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