"Now that the Large Hadron Collider is smashing lead, the discoveries are coming fast and furious.

Earlier this month CERN’s smashing machine switched from sending protons zinging around its ring to sending heavy lead ions at relativistic speeds. Those energetic collisions, the physicists now say, have allowed them to use the LHC’s ALICE experiment to glimpse quark-gluon plasma, the “primordial soup” present just after the Big Bang.

During this time, the Universe would have been so hot and energetic that the particles making up the elements we know today were unable to form, leaving the constituents to float “free” as a primordial soup. Quarks and gluons were only able to condense into larger particles when universal energy conditions were low enough. Hadrons (i.e. particles made from quarks; including baryons like neutrons and protons) were only allowed to form 10-6 seconds after the Big Bang.

In addition to creating the plasma, the CERN experiments have also shown they have the ability to probe the jets of particles that stream away from an energetic collision, and those jets could hold hints about the beginnings of the universe."

More: LHC Creates Cosmic Primordial Soup and Probes Strange Particle Jets

From: http://www.physorg.com/wire-news/524860 ... -time.html


This is a picture of lead-lead collision measured in the ATLAS detector at CERN. The collision contains two powerful "jets" of particles. The new result of ATLAS shows that these can "melt" at the temperatures achieved in the lead collisions of the LHC. Credit: CERN

The experiments at CERN have entered a new phase and have obtained the first results. In the giant particle accelerator, LHC, collisions have until now been with protons. The new experiments have been made with lead ions, 208 times heavier than a proton, that are collided at colossal energies. Danish scientists from the Niels Bohr Institute take part in the ATLAS experiment, where new results show, for the first time that the constituents of nuclei can melt. This shows how we think the world looked around a billionth of a second after the Big Bang. The results are published in Physical Review Letter.

The ATLAS experiment at the LHC is built to explore the fundamental nature of the universe. This exploration is carried out in two ways. One way is using lead ion collisions where the properties of nuclear matter are are studied at extreme temperatures. The other is to use proton collisions, which permit detailed studies, not only of matter, but also also directly probe the fundamental forces of Nature, which govern the evolution of the universe.

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"This is the first time we directly observe the nuclei melt and dissolve into the state you might call the primordial soup of the universe" a very happy physicist, Rasmus Mackeprang explains. He adds that this feels as if being on a journey through time to the beginning of the universe.

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