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arXiv · hep-lat/0208007

K^+ -> pi^+ pi^0 Decays on Finite Volumes and at Next-to-Leading Order in the Chiral Expansion

C. -J. D. Lin·G. Martinelli·E. Pallante·C. T. Sachrajda·G. Villadoro
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Abstract

We present the ingredients necessary for the determination of physical K->pi pi decay amplitudes for Delta I=3/2 transitions, from lattice simulations at unphysical kinematics and the use of chiral perturbation theory at next-to-leading order. In particular we derive the expressions for the matrix elements , where O_W is one of the operators appearing in the Delta S=1 weak Hamiltonian, in terms of low-energy constants at next-to-leading order in the chiral expansion. The one-loop chiral corrections are evaluated for arbitrary masses and momenta, both in full QCD and in the quenched approximation. We also investigate the finite-volume effects in this procedure.

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C. -J. D. Lin, G. Martinelli, E. Pallante, C. T. Sachrajda, G. Villadoro. 2002-11-22. K^+ -> pi^+ pi^0 Decays on Finite Volumes and at Next-to-Leading Order in the Chiral Expansion. https://doi.org/10.1016/s0550-3213(02)01038-6

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