Chiral perturbation theory , K → ππ decays and 2 + 1 flavor domain wall QCD

We present a calculation of the low energy constants describing the real and imaginary parts of the K → ππ decay amplitudes A0 and A2. Leading and next leading order chiral perturbation theory is used and its applicability assessed. A combination of statistical and systematic errors limits the precision of the results. The apparent limitations of chiral perturbation theory raise doubts about the accuracy of a possible extrapolation to physical K → ππ kinematics.