Narrator: This is Science Today. For the first time, a research team has detected a subatomic particle called the top quark without its antimatter partner. This discovery could help scientists better understand the fundamental nature of the universe. Research physicist Ann Heinsen of the University of California , Riverside co-led the team of fifty international scientists.

Heinson: What the group does – we're looking for is the top quarks produced on their own without their anti-particles, which has never been seen before.

Narrator: The team used the world's highest energy particle accelerator to detect the top quark – an ingredient of the ‘nuclear soup' caused by the Big Bang.

Heinson: Just after the Big Bang, there are several periods – all of which occur within a tiny fraction of a second, as the universe cooled and expanded, the energy became less and then different types of particles decoupled from other ones and so at that point when one might call it a nuclear soup is long before the particles have clustered together through gravity into stars and galaxies.

Narrator: For Science Today, I'm Larissa Branin.