The exotic material is more than a hundred thousand times hotter than the inside of the sun and is denser than a neutron star, one of the densest known objects in the universe.

"Besides black holes, there's nothing denser than what we're creating," said David Evans, a physicist at the University of Birmingham in the U.K. and a team leader for the LHC's ALICE detector, which helped observe the quark-gluon plasma.

"If you had a cubic centimeter of this stuff, it would weigh 40 billion tons."

By triggering hundreds of thousands of high-speed collisions each second, physicists using the LHC hope to break subatomic particles into even more basic forms of