Bottom quark ($b$)

The bottom quark $b$ is the third-generation down-type quark, with electric charge $-e/3$, spin $1/2$ and baryon number $1/3$. It is a heavy quark; its weak interaction decays make bottom-containing hadrons unstable. The charge assignment is listed alongside the other flavors in ^[ref].

A bottom quark combined with a light antiquark forms the minimal valence content of a bottom meson. Measuring the decay products and displaced decay point of such a hadron helps identify bottom production in a particle detector. The observed particles are hadrons and their descendants, rather than an isolated bottom quark propagating freely through the detector.