Protons and antiprotons comprise quarks, antiquarks and gluons. A proton-antiproton collision can produce a single top quark in two different ways: a quark and an antiquark can create a W boson, which then decays into a top quark and an anti-bottom quark. Or a gluon and a quark interact, with the quark emitting a W boson and the gluon creating a bottom quark and anti-bottom quark. The W boson then interacts with the bottom quark and produces a single top quark. In both cases, the top quark is short-lived and decays, for example, into a bottom quark, a lepton (such as a muon) and a neutrino. Credit: DZero collaboration