Mediator in an infinitesimal trade: Down for Up, and its brief existence comes to an end.
As all bosons, the W boson mediates one of the fundamental forces: the weak interaction, which allows particles to metamorphose.
When a Down quark turns into an Up quark, it involves a W boson that immediately decays into an electron and an anti-neutrino: a neutron has turned into a proton. This additional proton in the nucleus changes the atom, like cobalt decaying into nitrogen. A closer look at the radioactive decay of cobalt can even unveil that our universe violates parity.
How do particles transform?
Learn how to read Feynman diagrams!