After improving the knowledge about residua of the semileptonic form factor at its first two poles we show that $f_+^{Dpi}(q^2)$ is not saturated when compared with the experimental data. To fill the difference we approximate the rest of discontinuit
y by an effective pole and show that the data can be described very well with the position of the effective pole larger than the next excitation in the spectrum of $D^ast$ state. The results of fits with experimental data also suggest the validity of superconvergence which in the pole models translates to a vanishing of the sum of residua of the form factor at all poles. A similar discussion in the case of $Bto pi ell u_ell$ leads to the possibility of extracting $vert V_{ub}vert$, the error of which appears to be dominated by $g_{B^ast Bpi}$, which can be nowadays computed on the lattice. In evaluating the residua of the form factors at their nearest pole we needed the vector meson decay constants $f_{D^ast}$ and $f_{B^ast}$, which we computed by using the numerical simulations of QCD on the lattice with $N_{rm f}=2$ dynamical quarks. We obtain, $f_{D^ast}/f_D=1.208(27)$ and $f_{B^ast}/f_B=1.051(17)$.
We discuss the possibilities of assessing a non-zero $C_{7gamma}^prime$ from the direct and the indirect measurements of the photon polarization in the exclusive $b to sgamma^{(*)}$ decays. We focus on three methods and explore the following three de
cay modes: $B to K^*(to K_Spi^0)gamma$, $B to K_1(to Kpipi)gamma$, and $B to K^*(to Kpi)ell^+ell^-$. By studying different New Physics scenarios we show that the future measurement of conveniently defined observables in these decays could provide us with the full determination of $C_{7gamma}$ and $C_{7gamma}^prime$.
