Protons contain intrinsic charm quarks, a new study suggests

Protons may be intrinsically charming. The subatomic particles are a mash-up of three lighter particles called quarks: two of the type known as up quarks and one down quark. But physicists have speculated for decades that protons may also host more massive quarks, called “intrinsic” charm quarks. A new analysis supports that idea, physicists report in the Aug. 18 Nature. Charm quarks are much heav