Tests of Chiral Perturbation Theory in Rare Kaon Decays
  The neutral Kaon decays Ks->gamma gamma and Kl->pi0 gamma gamma are very sensitive to higher order loop effects of Chiral Perturbation Theory (ChPT). New measurements of the NA48 experiment show that ChPT contributions of O(p^6) cannot be neglected in these modes. In addition a new measurement of the related decay Kl->gamma gamma and an upper limit of the rate of Ks->pi0 gamma gamma are presented. 
Rainer Wanke (University of Mainz)