(a) In this reaction initially the total strangeness quantum number
Si = Sπ + Sp = 0 + 0 = 0, while for the final state
Sf = SK + SΣ = −1 + (−1) = −2
ΔS = −2. Therefore, the rule ΔS = 0 for strong interactions is violated.
(b) The total isospin for the initial state I = 0 + 0 = 0, while for the final state I = 0 + 1 = 1.
ΔI = 1. Therefore, the rule ΔI = 0 for strong interactions is violated.
