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q&a: the physics

How do high-energy nuclear collisions allow us to study the early universe?

Scientists believe that, in the fractions of a second after the Big Bang, the expanding matter was so hot and dense that protons and neutrons couldn't exist yet. Instead, the early universe was composed of tiny quarks and gluons, which in today's cool universe are confined to exist only within other particles like protons. Collisions of heavy nuclei at sufficiently high energies allow us to explore whether quarks and gluons do in fact become deconfined when subjected to high densities, and if so, what the properties of this quark-gluon matter are.

What is a quark-gluon plasma?

A quark-gluon plasma is, as its name implies, a plasma of quarks and gluons! Quarks are fractionally-charged particles that, in groups of 2 or 3, make up most of the particles known to exist (including protons and neutrons), and gluons are the particles that carry the strong force felt between quarks. Quarks and gluons, normally confined within other particles, are thought to be freed at very high densities, such as those created in high-energy nuclear collisions, for a tiny fraction of a second.

What is the connection between antimatter production and the birth of the universe?

Please read the story "Simple Maths, Antimatter, and the Birth of the Universe" written by Rebecca Siddall.

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webmaster Last modified: Jun 19 2013 10:36.