Elementary particle the fact that multiple bosons can occupy the same quantum state (Pauli exclusion principle). Also, bosons can be either elementary, like photons, or a combination, like mesons. The spin of bosons are integers instead of half integers. Gluons mediate the strong interaction, which join quarks and thereby form hadrons, which are either baryons (three quarks) or mesons (one quark and one antiquark). Protons and neutrons are baryons, joined by gluons to form the atomic nucleus. Like quarks, gluons exhibit color and anticolor—unrelated to the concept of visual color—sometimes in combinations, altogether eight variations of gluons. There are three weak gauge
Particle zoo as the Standard Model, and includes quarks, bosons and leptons. Particle zoo In particle physics, the term particle zoo is used colloquially to describe a relatively extensive list of the then known "elementary particles" by comparison to the variety of species in a zoo. In the history of particle physics, the situation was particularly confusing in the late 1960s. Before the discovery of quarks, hundreds of strongly interacting particles (hadrons) were known, and believed to be distinct elementary particles in their own right. It was later discovered that they were not elementary particles, but rather composites of the quarks. The