I am looking at the reactions of positive Kaons and am looking at $$K^+\to\pi^++\pi^0$$

Since the strangeness is not conserved, this has to be a Weak decay. When I try to make the Feynman diagrams for this decay, I cannot make one that is not a flavor changing neutral current. However, PDG says the fraction of this decay is $21\%$. This does not make sense as this is a very high fraction for a suppressed decay mode. What am I missing?

  • $\begingroup$ t channel? What have you tried? $\endgroup$ Commented Feb 24, 2020 at 3:49

1 Answer 1


enter image description here

Cabibbo suppressed, but not FCNC

(Apologies for poor drawing quality)


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