RHICrolled: Get Low

This is the first in an occassional series about Brookhaven’s Relativistic Heavy Ion Collider, or, as it’s affectionately called, RHIC.

Lil John has a theme song for RHIC’s latest experimental run.

Sorry, sorry! I couldn’t resist. RHIC’s actual ditty of the moment goes more like this. (Clean version, of course, RHIC doesn’t want any soap in its linac).

RHIC, which has a maximum potential energy of 200 billion electron volts (GeV), collided gold ions at energies as low as 7.7 GeV this spring — the lowest ever achieved in the machine. But why go so low?

Even at low energies, the gold-gold collisions at RHIC create a super hot, super dense environment that melts the bonds that hold normal nuclear matter together. The result is a new state of matter known as quark-gluon plasma (QGP).


At high energies, this transition from normal matter to QGP is smooth, like slowly melting butter sitting out in the sun. But at lower energies, physicists believe that there’s something called the “critical point,” below which QGP is formed in a much more violent process — think about throwing that piece of butter in the microwave for a minute or two. Physicists are searching for this landmark by scanning as many energies as possible. The low-energy run is a key part of that process.

You can read more here.