#negative proton

• Antiproton — The antiparticle of the proton, possessing identical mass and spin but an opposite, negative electric charge. Experimentally discovered in 1955, the antiproton is a stable composite particle belonging to the hadron class, composed of three antiquarks (two up antiquarks and one down antiquark), whose direct interaction with ordinary matter leads to mutual annihilation, releasing massive energy in the form of gamma rays.