Charmonium contribution to $B \rightarrow K\ell^+\ell^-: testing the factorization approximation on the lattice

TL;DR

This study uses lattice QCD to evaluate charmonium effects in B meson decays, testing the factorization approximation and finding indications of its violation in the low momentum transfer region.

Contribution

The paper provides the first lattice QCD analysis of charmonium contributions to B decays, specifically testing the factorization approximation in this context.

Findings

Results indicate a violation of the factorization approximation.

Focus on low q^2 region with small b-quark mass to control divergences.

Renormalization constants calculated for relevant four-quark operators.

Abstract

We report the current status of a study of charmonium contribution to $B \rightarrow K\ell^+\ell^-$ on the lattice. Our lattice calculation tests the factorization approximation for this contribution. In order to control the problem of the artificial divergence, we focus on the low $q^2$ region with a small b-quark mass. We also take into account the renormalization constants of relevant four-quark operators calculated through the temporal moments. Results suggest a violation of the factorization approximation.