Pion G-parity
= Pion G-parity
{title2=$G_\pi=-1$}
The neutral <pion> has positive <charge conjugation> <eigenvalue> and its spin-one <isospin> half-turn has <eigenvalue> minus one. Hence the <G parity> <eigenvalue> is minus one. Since G parity commutes with <isospin>, both charged members have the same value. Charged-state phase changes alter individual charge-conjugation and rotation formulas together, leaving this <eigenvalue> unchanged.