Chasing particles with tiny electric charges

All known elementary particles have electric charges that are integer multiples of a third of the electron charge. But some theories predict the existence of "millicharged" elementary particles that would have a charge much smaller that the electron charge and could account for the elusive dark matter that fills the universe. An international team of researchers has now reported the first search at the Large Hadron Collider (LHC)--and more generally at any hadron collider--for elementary partic...