type of weak interaction

conserved additive quantum number

selection rule in weak interaction

pure leptonic

F, H_L

null

pure hadronic

F, H

1) ΔS = ∓1, ΔI = ±1/2, ΔI₃ = ±1/2.

2) ΔS = ∓2, ΔI₃ = ±1

fermionic

F

1) ΔS = ΔQ_h = ±1, ΔI = ±1/2, ΔI₃ = ±1/2

2) ΔS = 0, ΔI = ±1, ΔI₃ = ±1