Antineutron, antiparticle of the neutron. The neutron has no electric charge, and thus so does the antineutron. However, the neutron consists of one up quark (charge +2/3) and two down quarks (charge –1/3), and the antineutron consists of one anti-up quark (charge –2/3) and two anti-down quarks (charge +1/3).

Do antiparticles exist?

Antimatter detectives

For each basic particle of matter, there exists an antiparticle with the same mass, but the opposite electric charge. The negatively charged electron, for example, has a positively charged antiparticle called the positron.

Is antimatter made of antiquarks?

That's why quarks (which each have baryon number of +1/3), electrons, muons, taus, and neutrinos (which each have lepton number of +1) are all matter, while antiquarks, positrons, anti-muons, anti-taus, and anti-neutrinos are all antimatter.