Large Hadron Collider scientists observe new 'exotic' particles

The physics lab that's home to the world's largest atom smasher has announced the observation of three new, never-before-seen "exotic particles," which could provide clues about the force that binds subatomic particles together.

The research collaboration, called the Large Hadron Collider experiment (LHCb), located at CERN near Geneva, Switzerland, has observed a new kind of "pentaquark" and the first-ever duo of "tetraquarks."

Quarks are elementary particles, which CERN explains usually combine together in groups of twos and threes to form hadrons such as the protons and neutrons that make up atomic nuclei. More rarely, however, they can also combine into four-quark and five-quark particles, or "tetraquarks" and "pentaquarks."

The announcement comes amid a flurry of activity this week at CERN, as scientists resumed smashing together particles in what is expected to be nearly four years of operation in "Run 3" — the third time the LHC has carried out collisions since its debut in 2008.

The so-called "Run 3" ends a three-year pause for maintenance and other checks, and is operating at an unprecedented energy of 13.6 trillion electronvolts, which will offer the prospect of new discoveries in particle physics.

Earlier this week, CERN celebrated the 10-year anniversary of the confirmation of the Higgs boson, the subatomic particle that has a central place in the so-called Standard Model that explains the basics of particle physics.