Form factors for $B\to j_1{j}_2$ decays into two currents in QCD

Abstract

We discuss the general properties of the $B$-meson decay form factors $F(q^2,q^{\prime 2})$, describing $B$-meson decays induced by two currents, e.g., $B$-decays into four leptons in the final state. We study the analytic properties of these complicated objects and identify those regions of $q^2$ and $q^{\prime 2}$, where perturbative QCD can be applied for obtaining predictions for the physical form factors.

9 pages, version to appear in Physical Review D