I ( Λ ) = 1 / 2
I ( Σ ) = 1 / 2
I ( Ξ ) = 1 / 2
I ( K ) = 1
I ( γ ) = 1
I ( π ) = 1
I ( l ) = 1 for lepton l
I ( p ) = 1 / 2 , I ( n ) = 1 / 2
but I ( u d ) = I ( d d ) = I ( u u ) = 1
I ( η ) = 1