$B\to \rho \ell {\nu }_{\ell }$ Form Factors

Abstract

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.

Comments: 15 pages, Latex, 4 figures