Test of factorization for the long-distance effects from charmonium on $B\to K\ell^+\ell^-$

TL;DR

This paper uses lattice simulations to evaluate the charmonium effects on the decay B→Kℓ+ℓ−, testing the factorization approximation and revealing potential discrepancies in non-factorizable contributions.

Contribution

First lattice-based calculation of charmonium effects on B→Kℓ+ℓ− decay focusing on the low q² region and testing the factorization approximation.

Findings

Possible discrepancy between lattice results and factorization for non-factorizable effects.

Lattice simulations provide new insights into long-distance contributions in B decays.

Assessment of the factorization approximation's validity in this context.

Abstract

We report on a calculation of the charmonium contribution to the decay $B \rightarrow K\ell^+\ell^-$ using lattice simulations with 2+1 flavors of Mobius domain wall fermions. We focus on the region of $q^2$ below the $J/\psi$ resonance and test the factorization approximation to estimate the amplitude. We show a possible discrepancy between the lattice calculation and the factorization method for the non-factorizable contribution.