Hadron era

The early-universe epoch when quarks bound into hadrons, which dominated matter before most matter and antimatter annihilated.

Quark–gluon plasma: A state of matter in which quarks and gluons are not confined within individual hadrons. The hot state that preceded hadron formation as the universe expanded and cooled.
Hadron: A composite particle made of quarks bound by the strong interaction. Hadrons became the dominant matter particles after the quark epoch.
Big Bang: The hot, dense early state of the universe and its subsequent expansion. The hadron era was one stage in the universe’s early expansion and cooling.
Baryon asymmetry: The observed excess of matter over antimatter, especially the excess of baryons over antibaryons. This imbalance allowed a small fraction of hadronic matter to survive annihilation.
Quantum chromodynamics: The theory describing the strong interaction among quarks and gluons. Its confinement dynamics enabled quarks to form hadrons during this epoch.
Baryon: A hadron made of three quarks, such as a proton or neutron. Baryons and antibaryons were the massive matter–antimatter pairs later depleted by annihilation.
Planck epoch: The earliest proposed interval of cosmic history, when quantum-gravity effects would have dominated. It marks a much earlier regime than the particle-physics epochs that include hadron formation.
Cosmic microwave background: The relic radiation released when the early universe became transparent to photons. Its measured properties constrain the later cosmic history of the matter left by early annihilations.
Confinement (physics): The phenomenon that prevents isolated quarks and gluons from being observed at low energies. Cooling brought the universe into the regime where confinement assembled hadrons.
Meson: A hadron made of a quark and an antiquark. Mesons formed alongside baryons and were prominent products of early-universe reactions.

Linked from 2 pages