Relationship between the quark condensate and low-energy Pi-Pi   observables beyond O(p^4)
  The two-flavor Gell-Mann-Oakes-Renner ratio is expressed in terms of low-energy pi-pi observables including the O(p^6) double chiral logarithms, computed in Generalized Chiral Perturbation Theory. It is found that their contribution is important and tends to compensate the one from the single chiral logarithms. 
Luca Girlanda (Barcelona, Autonoma U.)