# What type of symmetry specifies in presence of what each not-charged particle (for example, neutrino) should have an antiparticle?

I think that charging symmetry assumes antiparticle presence, which has an opposite charge sign . And what symmetry assumes existence of an antiparticle at a neutral particle

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See also this question. –  Peter Shor Dec 2 '11 at 1:00
Would it be possible to clarify the question title? And the question body, for that matter? I don't quite understand what it's asking... –  David Z Dec 2 '11 at 9:39