Bounding heavy meson form factors using inclusive sum rules

We utilize inclusive sum rules to construct both upper and lower bounds on the form factors for B → D, D∗, ϱ, π, ω, K and K∗ semi-leptonic and radiative decays. We include the leading nonperturbative 1E corrections and point out cases when αs corrections are equally important. We compute the αs correction to the lower bound on the B → D∗ form factor f(w) at zero recoil, thereby constraining its normalization f(1) to within 6–8% of the upper bound. We show that the B → ϱ form factor α+ is suppressed at small momentum transfer by either a factor of 1E or αs. These bounds can be used to rule out phenomenological models as well as to determine values for the CKM matrix elements once radiative corrections are included.