Analyticity properties and unitarity constraints of heavy meson form factors

Abstract
We derive new bounds on the b-number form factor F(q2) of the B meson for q2 values relevant to the kinematics of the decays B¯→Dlν¯l and B¯→D*lν¯l. The new bounds take into account the experimentally known properties of the Υ states below the onset of the physical B¯B threshold.