Three cousins join family of four-quark particles
Large Hadron Collider finds heavier versions of strange-charm combinations
An exotic particle now has three new cousins, making for a happy family of four.
Scientists with the LHCb experiment, located at the Large Hadron Collider near Geneva, announced the discovery of the particle’s new cousins in two papers published online at arXiv.org on June 25. The particles are each made up of four quarks, elementary particles known for their role as the building blocks of protons and neutrons.
The previously known particle, X(4140), and its cousins — X(4274), X(4500) and X(4700) — are composed of two charm quarks and two strange quarks. Each particle’s quarks are arranged in configurations of increasingly higher energy, making each particle heftier than the last — thanks to the equivalence of mass and energy expressed by the equation E=mc2.