The antineutron is the antiparticle of the neutron with symbol . It differs from the neutron only in that some of its properties have equal magnitude but opposite sign. It has the same mass as the neutron, and no net electric charge, but has opposite baryon number (+1 for neutron, -1 for the antineutron). This is because the antineutron is composed of antiquarks, while neutrons are composed of quarks. In particular, the antineutron consists of one up antiquark and two down antiquarks.

Das Antineutron ist im Standardmodell das Antiteilchen des Neutrons. Nach dem Quarkmodell besteht es aus zwei Anti-Down-Quarks und einem Anti-Up-Quark.

L'antineutron est l'antiparticule du neutron. L'antineutron possède la même masse et la même charge que le neutron, mais est composé d'antiquarks.

Antyneutron - antycząstka neutronu.

L'antineutrone è l'antiparticella del neutrone. Fu per la prima volta rivelato da Bruce Cork nel 1956, un anno dopo la scoperta dell'antiprotone.