CERN Discovers First-Ever Particle of Four 'Charm' Quarks

GENEVA — A team of scientists made the first-ever sighting of an exotic particle by using the Large Hadron Collider at Europe's CERN. According to the study in the Arxiv preprint server, the particle is made of two charm quarks and two charm antiquarks.

The Large Hadron Collider's superconductors accelerate protons to crash them together at near-light speeds. Writing in a news release, CERN says the team then filtered out ordinary background collisions and looked for "bumps," or excess collisions, which led to the particle.

Quarks are elementary particles that serve as the building blocks of all matter, but most naturally existing matter, such as protons and neutrons, is made of three quarks or fewer. A particle formed by four heavy quarks of the same type has never been seen before.

CERN cautions that it is not known if the exotic particle is a pair of charm quarks held together by a weak bond, or a system of four quarks held together by strong bonds known as a true tetraquark.