The very size of helium-3 is enough to ensure that the collective behavior generated by forces between quarks at the start of the collision cannot extend over the entire nuclei. The difference in symmetry between the three experiments generates a different flow in the fluid. The experiments, conducted at the Relativistic Heavy Ion Collider, fell into three categories: colliding protons with gold, colliding deuterons (a proton and a neutron) with gold, and colliding helium-3 nuclei (two protons and a neutron) with gold. The experimental results could then be compared to extensive calculations using multiple models. Advertisementįor the researchers to determine if they had the real McCoy, they had to vary the conditions under which they created the quark-gluon plasma. This collective behavior generates global properties in the later collision that look like a quark-gluon plasma but are not. In this interpretation of the evidence, at the start of the collision, the quark-quark interactions set up a collective behavior. Unfortunately, theorists suggested that the same evidence might be obtained via the collisional process that creates the fluid in the first place.
So a common way to look for a quark-gluon plasma is to look for evidence of flow without viscosity. Fluids with no viscosity at all, like superfluids, have some really weird properties. One property of a quark-gluon plasma is that it flows without viscosity-viscosity is the internal friction of a fluid that makes honey thick and slow-flowing, while water is fast and free-flowing. Essentially, a quark-gluon plasma takes time to form, while the energy and size of collisions among small atoms didn’t seem to allow time for the plasma to form. Yes, some experiments were definitely quark-gluon plasmas, but some experiments were more ambiguous. Interpreting this evidence requires a model, and the models for quark interactions are a bit insane in terms of difficulty, leaving things open to multiple explanations. As detectors were upgraded, new experiments revealed more and more details. Following LHC observations, the folks at the Relativistic Heavy Ion Collider reexamined their data and found that they, too, seem to make a quark-gluon plasma without needing heavy atoms. But then the Large Hadron Collider came along and found that there might be signs of this material in collisions with light atoms.
Recreation of the early Universe in the form of quark-gluon plasmas was first reported in collisions of heavy atoms by teams at the Relativistic Heavy Ion Collider. Quarks and gluons were all jumbled up, but the gluons could not hold the quarks together. In the early Universe, however, there was simply too much energy to hold a family gathering. As long as there are gluons around, the quarks will turn up to family reunions and make nice with each other. The quark family members are all charged, so they don’t really like each other that much.
All of these particles are a bit like Legos: put them together in various ways to create a Universe (the instruction book can be a bit overwhelming though). On the other side we have a charming family of colorful quarks. Then there are the force carriers: photons, W and Z bosons, the Higgs, and gluons. On one side, we have the leptons: electrons and their overweight cousins, muons and tauons (and their invisible friends, a corresponding neutrino). The Universe is divided into families of particles. Now, it seems that science has done its job and done the experiments to confirm that, yes, those observations were almost certainly quark-gluon plasmas. We’ve observed these in the lab, but those findings are not without controversy-the quark-gluon plasma seemed to form under unexpected conditions. And that left us with quarks and gluons flying around to form something called a quark-gluon plasma.
Even protons and neutrons could not survive. The Universe was so dense and hot that atoms and nuclei could not form-they would be ripped apart by high-energy collisions.