K \to \pi\pi decay amplitudes from the lattice

Abstract

In order to directly compute physical two-pion K-decay amplitudes using lattice methods we must prepare a two-pion state with non-zero relative momentum. Building upon a proposal of Lellouch and Lüscher, we describe a finite-volume method to realize such a state as the lowest energy state of two pions.

Comments: 3 pages, Lattice 2002(WME)