A quark (from within a proton) and an antiquark (from an antiproton) colliding at high energy can annihilate to produce a top quark and a top antiquark, which then decay into other particles.

• Frame 1: One of the proton's quarks and one of the antiproton's antiquarks are heading toward a collision.
• Frame 2: The quark and antiquark collide and annihilate....
• Frame 3: ...into virtual gluons.
• Frame 4: A top and antitop quark emerge from the gluon cloud.
• Frame 5: These quarks begin moving apart, stretching the color force field (gluon field) between them.

• Frame 6: Before the top quark and antiquark have moved very far, they decay into a bottom and antibottom quark (respectively) with the emission of W force carrier particles.
• Frame 7: The new bottom quark and antibottom quark rebound away from the emitted W force carrier particles.

• Frame 8: An electron and neutrino emerge from the virtual W^- boson, and an up quark and down antiquark emerge from the virtual W⁺ boson.
• Frame 9: The bottom quark and bottom antiquark, electron, neutrino, up quark, and down antiquark all move away from one another.

What is wrong with this picture? [ Answer ]

The intermediate stages of this process occur in about a billionth of a billionth of a billionth of a second, and are not observable.