According to the theory, matter can only be created in particle-antiparticle pairs.
依照理论，物质只能在粒子-反粒子对中产生。
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He further predicted that every elementary particle with a spin has its counterpart with the same mass but opposite electric charge, or that a particle has an antiparticle.
Thecurrent "standard model" of physics holds that each particle -protons, electrons, neutrons and a zoo of more exotic particles - has itsmirror image antiparticle.