1. The problem statement, all variables and given/known data Which of the folowing decays are forbidden by C-iinvariance ω° = π° + γ η' = ρ° + γ π° = γ +γ + γ 2. Relevant equations None 3. The attempt at a solution The answers are meant to be: ω° = π° + γ -1 : (+1) (-1) -> Allowed η' = ρ° + γ +1 -> (-1) (-1) -> Allowed π° = γ +γ + γ +1 -> (-1)(-1)(-1) -> forbidden My question is where are those +1 and -1 gotten from, I have tried to find what values to put for the particles but cannot fund them anywhere. Does anyone know if the three are right and if so where I can get the +1 or -1?