= Meson parity and charge conjugation
{title2=$P=(-1)^{L+1},\quad C=(-1)^{L+S}$}
For an ordinary <quark>-<antiquark> <meson>, opposite <intrinsic parities> and <orbital parity> give $P=(-1)^{L+1}$. For a self-conjugate flavor state, <charge conjugation> exchanges the two constituents. Reversal of their relative momentum gives $(-1)^L$, spin exchange gives $(-1)^{S+1}$, and reordering the two fermionic creation operators gives one extra minus sign. Their product is $C=(-1)^{L+S}$. Electrical neutrality alone does not imply that a state is an eigenstate of charge conjugation; charged mesons have no individual C eigenvalue.
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