2012/11/02 by Maxwell T. Hansen, Hansen, Maxwell T., Stephen R. Sharpe +1 · 3 citations
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #hep-lat
paper · pdf · doi:10.48550/arxiv.1211.0511
Conference proceedings
arxiv created 2012/11/02 · arxiv updated 2012/11/05
We describe a generalization of the Lellouch-Lüscher formula to the case of multiple strongly-coupled decay channels. As in the original formula, our final result is a relation between weak matrix elements in finite and infinite volumes. Our extension is limited to final states with two scalar particles, with center of mass energies below the lowest three- or four-particle threshold. Otherwise the extension is general, accommodating any number of channels, arbitrary strong coupling between channels, as well as any form of weak decay operators in the matrix elements. Among many possible applications, we emphasize that this is a necessary first step on the way to a lattice-QCD calculation of weak decay rates for D -> pi pi and D -> K K-bar. Our results allow for arbitrary total momentum and hold for degenerate or non-degenerate particles.