$B \to \rho \ell \nu_\ell$ Form Factors
  The bounds on the form factors for $B \to \rho \ell \nu_\ell$ decay are studied. Constrained by lattice data and a constrained conformal mapping, the more informations can be obtained for $A_1(q^2)$ form-factor which dominates the decay rate at large $q^2$. Specifically, we confirm a moderately increasing behavior of this form factor. 
Damir Becirevic