Physics Question #350

David Keirsey, a 48 year old male from the Internet asks on February 27, 1998,

What are the quantum numbers that are involved in the distinction between matter and antimatter? I know that a particle and anti-particle must have the same mass (or no mass) and opposite charge (or neutral) and I think opposite spin. What other quantum numbers are involved?

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The answer

Jess Brewer answered on February 27, 1998

Antiparticles have the same mass and spin, opposite charge and opposite baryon number (if any), lepton number (if any), strangeness (if any), charm (if any), truth (if any), beauty (if any) and any other hitherto undiscovered "additive" quantum numbers. If someone discovers an additive quantum number that violates this rule, that would be significant - and I think there is a fundamental theorem that says that can't happen.

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