$K \to \pi\pi\gamma$ decays: a search for novel couplings in kaon decays
  We analyze $K \to \pi\pi\gamma$ decays in the framework of Chiral Perturbation Theory. We study the different Dalitz plot distributions, trying to find regions where o($p^6$) contributions could be more easily detected. To fulfill this program we compute all the the o($p^4$) loop and counterterm contributions, finding a substantial agreement with the existing calculations and adding some small missing terms in $K_S \to \pi\pi\gamma$. 
Giancarlo D'Ambrosio and Gino Isidori