Low energy constants describing the weak, two-pion decays of K mesons in chiral perturbation theory are computed using 2+1 flavors of domain wall fermions in a finite volume with spatial extent 2.74 fm and for a single inverse lattice spacing 1/a = 1.73 GeV. Partially quenched perturbation theory is used in both leading and next-to-leading order. The non-perturbative regularization independent RI/MOM renormalization scheme is employed to determine these low energy constants in the continuum, RI normalization scheme with 20% statistical errors but systematic errors which are estimated to lie between 50 and 100% depending on the operator. These low energy constants are then used to estimate the DeltaI = 1/2 and DeltaI = 3/2 K → pipi decay matrix elements and epsilon'/epsilon. The poor convergence of chiral perturbation theory for quark masses as large as that of the strange quark severely limits the accuracy of these results. |